Added support for svn in prompt
Added support for svn in prompt

This changes the fish_prompt in a way that the prompt in svn working copys looks like in a git checkout (branchname and revision is shown)
FabioAntunes/theme-agnoster,oh-my-fish/theme-agnoster,decors/shellder,WBTMagnum/theme-agnoster,rubenvarela/theme-agnoster,scorphus/theme-agnoster