feat: allow all network properties to be globally set

Global settings are cool if managed in a standard way (ugh env vars) so we'll add them back for golang plugins as necessary.

docs/networking/network.md

@@ -148,12 +148,22 @@ dokku network:set node-js-app attach-post-deploy
 dokku network:set node-js-app initial-network
 ```
 
-Finally, the `initial-network` property can be set globally by using the `--global` flag in place of the app name.
+The network properties can also be set globally. The global default is emty string, and the global value is used when no app-specific value is set.
 
 ```shell
+dokku network:set --global attach-post-create global-create-network
+dokku network:set --global attach-post-deploy global-deploy-network
 dokku network:set --global initial-network global-network
 ```
 
+The default value may be set by passing an empty value for the option.
+
+```shell
+dokku network:set --global attach-post-create
+dokku network:set --global attach-post-deploy
+dokku network:set --global initial-network
+```
+
 #### Network Aliases
 
 When a container created for a deployment is being attached to a network - regardless of which `attach` property was used - a network alias of the pattern `APP.PROC_TYPE` will be added to all containers. This can be used to load-balance requests between containers. For an application named `node-js-app` with a process type of web, the network alias - or resolvable DNS record within the network - will be:
@@ -172,7 +182,7 @@ Dockerfile-based applications may listen on other ports. For more information on
 
 #### Specifying a custom TLD
 
-When attaching applications to networks, a custom TLD can be specified via the `network:set` command. This TLD is suffixed to the network alias for the application/process-type combination for _all_ networks to which the application is attached, and cannot be customized per network.
+When attaching applications to networks, a custom TLD can be specified via the `network:set` command. This TLD is suffixed to the network alias for the application/process-type combination for _all_ networks to which the application is attached, and cannot be customized per network. The default value is an empty string.
 
 To specify a TLD of `svc.cluster.local` for your application, run the following command:
 
@@ -189,6 +199,24 @@ node-js-app.web.svc.cluster.local
 
 Note that this has no impact on container port handling, and users must still specify the container port when making internal network requests.
 
+The default value may be set by passing an empty value for the option:
+
+```shell
+dokku network:set node-js-app tld
+```
+
+The `tld` property can also be set globally. The global default is emty string, and the global value is used when no app-specific value is set.
+
+```shell
+dokku network:set --global tld svc.cluster.local
+```
+
+The default value may be set by passing an empty value for the option.
+
+```shell
+dokku network:set --global tld
+```
+
 #### When to attach containers to a network
 
 Containers can be attached to a network for a variety of reasons:
@@ -297,6 +325,18 @@ CONTAINER ID        IMAGE                      COMMAND                CREATED
 d6499edb0edb        dokku/node-js-app:latest   "/bin/bash -c '/star   About a minute ago   Up About a minute   0.0.0.0:49153->5000/tcp   node-js-app.web.1
 ```
 
+The `bind-all-interfaces` property can also be set globally. The global default is `false`, and the global value is used when no app-specific value is set.
+
+```shell
+dokku network:set --global bind-all-interfaces true
+```
+
+The default value may be set by passing an empty value for the option.
+
+```shell
+dokku network:set --global bind-all-interfaces
+```
+
 ### Displaying network reports for an app
 
 You can get a report about the app's network status using the `network:report` command:
@@ -307,14 +347,56 @@ dokku network:report
 
 ```
 =====> node-js-app network information
-       Network bind all interfaces: false
-       Network listeners: 172.17.0.1:5000
+       Network attach post create:
+       Network attach post deploy:
+       Network bind all interfaces:   false
+       Network computed attach post create:
+       Network computed attach post deploy:
+       Network computed bind all interfaces:false
+       Network computed initial network:
+       Network computed tld:
+       Network global attach post create:
+       Network global attach post deploy:
+       Network global bind all interfaces:false
+       Network global initial network:
+       Network global tld:
+       Network initial network:
+       Network tld:
+       Network web listeners: 172.17.0.1:5000
 =====> python-sample network information
-       Network bind all interfaces: false
-       Network listeners: 172.17.0.2:5000
+       Network attach post create:
+       Network attach post deploy:
+       Network bind all interfaces:   false
+       Network computed attach post create:
+       Network computed attach post deploy:
+       Network computed bind all interfaces:false
+       Network computed initial network:
+       Network computed tld:
+       Network global attach post create:
+       Network global attach post deploy:
+       Network global bind all interfaces:false
+       Network global initial network:
+       Network global tld:
+       Network initial network:
+       Network tld:
+       Network web listeners:          172.17.0.2:5000
 =====> ruby-sample network information
-       Network bind all interfaces: true
-       Network listeners:
+       Network attach post create:
+       Network attach post deploy:
+       Network bind all interfaces:   false
+       Network computed attach post create:
+       Network computed attach post deploy:
+       Network computed bind all interfaces:false
+       Network computed initial network:
+       Network computed tld:
+       Network global attach post create:
+       Network global attach post deploy:
+       Network global bind all interfaces:false
+       Network global initial network:
+       Network global tld:
+       Network initial network:
+       Network tld:
+       Network web listeners:
 ```
 
 You can run the command for a specific app also.
@@ -325,8 +407,22 @@ dokku network:report node-js-app
 
 ```
 =====> node-js-app network information
-       Network bind all interfaces: false
-       Network listeners: 172.17.0.1:5000
+       Network attach post create:
+       Network attach post deploy:
+       Network bind all interfaces:   false
+       Network computed attach post create:
+       Network computed attach post deploy:
+       Network computed bind all interfaces:false
+       Network computed initial network:
+       Network computed tld:
+       Network global attach post create:
+       Network global attach post deploy:
+       Network global bind all interfaces:false
+       Network global initial network:
+       Network global tld:
+       Network initial network:
+       Network tld:
+       Network web listeners: 172.17.0.1:5000
 ```
 
 You can pass flags which will output only the value of the specific information you want. For example: