Thanks Torsten Rupp (rupp) for the patch!
This patch adds the abilities to sort the bone group list in the
properties panel and to move bone groups up/down in the list (similar
like for vertex groups)
ui/ --> startup/bl_ui
op/ --> startup/bl_operators
scripts/startup/ is now the only auto-loading script dir which gives some speedup for blender loading too.
~/.blender/2.56/scripts/startup works for auto-loading scripts too.