Merge branch 'maint' of git://repo.or.cz/git-gui into maint
* 'maint' of git://repo.or.cz/git-gui:
git-gui: Work around bad interaction between Tcl and cmd.exe on ^{tree}
git-gui: Don't linewrap within console windows
git-gui: Correct ls-tree buffering problem in browser
git-gui: Skip nicknames when selecting author initials
git-gui: Ensure windows shortcuts always have .bat extension
git-gui: Include a Push action on the left toolbar
git-gui: Bind M1-P to push action
git-gui: Don't bind F5/M1-R in all windows
git-gui: Unlock the index when cancelling merge dialog
git-gui: properly popup error if gitk should be started but is not installed