We had an issue with third party plugins installing things via apt while
already installing dokku itself via apt.
To resolve this, `plugins-install` and `plugins-install-dependencies`
now can take a `--core` flag allowing to execute the install hook only
on core plugins and not on third party plugins.
Another feature with this modification is the ability to disable/enable
plugins. Two new commands now exist:
* `plugins:enable <name>` to enable a previously disabled plugin
* `plugins:disable <name>` to disable an installed plugin. This won’t
work on core plugins.
This reverts commit 1bf30bdcb1.
Commit was reverted as this breaks installs of core plugins. It is also a hack around broken plugins that don't use the `dependencies` pluginhook.
All core plugins that require debian packages already have those packages specified in the `depends` stanza of the `control` file, so no need to respecify them here.
