Merge git://git.kernel.org/pub/scm/gitk/gitk

* git://git.kernel.org/pub/scm/gitk/gitk:
  [PATCH] Provide configurable UI font for gitk
  [PATCH] gitk: Use git wrapper to run git-ls-remote.
  [PATCH] gitk: add key bindings for selecting first and last commit
  gitk: Add a help menu item to display key bindings
  [PATCH] gitk: allow goto heads
  gitk: replace parent and children arrays with lists