refactor: decrease compile time for golang plugins

This change refactors the compiled golang plugins into 3 distinct binaries:

- commands: already existing
- subcommands/subcommands: entrypoint into all subcommands
- triggers: entrypoint into all triggers

It then further symlinks triggers and subcommands to the built binaries. This results in both a much faster build process as well as smaller package size.

plugins/repo/subcommands.go

@@ -0,0 +1,37 @@
+package repo
+
+import (
+	"errors"
+	"strings"
+
+	"github.com/dokku/dokku/plugins/common"
+)
+
+// CommandGc runs 'git gc --aggressive' against the application's repo
+func CommandGc(appName string) error {
+	if appName == "" {
+		return errors.New("Please specify an app to run the command on")
+	}
+	err := common.VerifyAppName(appName)
+	if err != nil {
+		return err
+	}
+
+	appRoot := strings.Join([]string{common.MustGetEnv("DOKKU_ROOT"), appName}, "/")
+	cmdEnv := map[string]string{
+		"GIT_DIR": appRoot,
+	}
+	gitGcCmd := common.NewShellCmd("git gc --aggressive")
+	gitGcCmd.Env = cmdEnv
+	gitGcCmd.Execute()
+	return nil
+}
+
+// CommandPurgeCache deletes the contents of the build cache stored in the repository
+func CommandPurgeCache(appName string) error {
+	if appName == "" {
+		common.LogFail("Please specify an app to run the command on")
+	}
+
+	return PurgeCache(appName)
+}