git-svn: sort the options in the --help message.
git-svn: sort the options in the --help message.

"git svn <cmd> --help" gave options in the order they were found in a
Perl hash, which meant "randomly" to humans.

Signed-off-by: Benoit Sigoure <1e23a9b864bbfcd2c432e234ca9d6011db05a743@lrde.epita.fr>
Acked-by: Eric Wong <8c2951295f8292b0c03727bc4652981172298eae@yhbt.net>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git