git-gui 0.20.0

* tag 'gitgui-0.20.0' of http://repo.or.cz/r/git-gui:
  git-gui: set version 0.20
  git-gui: sv.po: Update Swedish translation (547t0f0u)
  git-gui i18n: Updated Bulgarian translation (547t,0f,0u)
  git-gui: Makes chooser set 'gitdir' to the resolved path
  git-gui: Fixes chooser not accepting gitfiles
  git-gui: reinstate support for Tcl 8.4
  git-gui: fix problem with gui.maxfilesdisplayed
  git-gui: fix verbose loading when git path contains spaces.
  git-gui/gitk: Do not depend on Cygwin's "kill" command on Windows
  git-gui: add configurable tab size to the diff view
  git-gui: Make git-gui lib dir configurable at runime
  git-gui i18n: Updated Bulgarian translation (520t,0f,0u)
  L10n: vi.po (543t): Init translation for Vietnamese
  git-gui: align the new recursive checkbox with the radiobuttons.
  git-gui: Add a 'recursive' checkbox in the clone menu.