Add missing sub-subcommands to subcommand help outputs

Author: bmcdonnell

git-flow-bugfix

@@ -57,6 +57,7 @@ git flow bugfix rebase
 git flow bugfix checkout
 git flow bugfix pull
 git flow bugfix delete
+git flow bugfix rename
 
 Manage your bugfix branches.
 

git-flow-feature

@@ -57,6 +57,7 @@ git flow feature rebase
 git flow feature checkout
 git flow feature pull
 git flow feature delete
+git flow feature rename
 
 Manage your feature branches.
 

git-flow-hotfix

@@ -53,6 +53,9 @@ git flow hotfix start
 git flow hotfix finish
 git flow hotfix publish
 git flow hotfix delete
+git flow hotfix rebase
+git flow hotfix track
+git flow hotfix rename
 
 Manage your hotfix branches.
 

git-flow-release

@@ -417,8 +417,10 @@ usage() {
 git flow release [list]
 git flow release start
 git flow release finish
+git flow release branch
 git flow release publish
 git flow release track
+git flow release rebase
 git flow release delete
 
 Manage your release branches.

git-flow-support

@@ -50,6 +50,7 @@ usage() {
 		OPTIONS_SPEC="\
 git flow support [list]
 git flow support start
+git flow support rebase
 
 Manage your support branches.