Fossil: Improve branch name detection (#497)
Fossil: Improve branch name detection (#497)

It's more efficient and avoid a lot of wrong branch detection due to tag
mismatch.

smadhueagle/liquidprompt,jaesivsm/liquidprompt,tsbarnes/liquidprompt,joshuarubin/dotfiles,pkkolos/liquidprompt,dtschan/liquidprompt,laurentbardin/liquidprompt,joshuarubin/dotfiles,milouse/liquidprompt,dan-cleinmark/liquidprompt,nojhan/liquidprompt,alexprengere/liquidprompt,joshuarubin/dotfiles,joshuarubin/dotfiles,dpilone/liquidprompt