Merge branch 'maint'

Merge branch 'maint'

* maint:
  Use gunzip -c over gzcat in import-tars example.
  git-gui: Don't crash in citool mode on initial commit.
  git-gui: Remove TODO list.
  git-gui: Include browser in our usage message.
  git-gui: Change summary of git-gui.
  git-gui: Display all authors of git-gui.
  git-gui: Use mixed path for docs on Cygwin.
  git-gui: Correct crash when saving options in blame mode.
  git-gui: Expose the browser as a subcommand.
  git-gui: Create new branches from a tag.
  git-gui: Prefer version file over git-describe.
  git-gui: Print version on the console.
  git-gui: More consistently display the application name.
  git-gui: Permit merging tags into the current branch.
  git-gui: Basic version check to ensure git 1.5.0 or later is used.
  git-gui: Refactor 'exec git subcmd' idiom.