Support private and proposed update branches

[mbauhardt]

I love the usage of git feature|bug|refactor. But it would be nice to have the same for private branches like

<username>/<branchname> 

and proposed update branches

pu/<branchname> 

Because those branches are good markers (when they are online/pushed to remote) that these branches are maybe rebased and should not touched by another developer.

[adrian-gierakowski]

you can do git alias myfeature"feature -a my-name/feature-name"

and then

git myfeature feature-name
git checkout master 
git myfeature finish feature-name