git-p4: ensure submit clientPath exists before chdir
git-p4: ensure submit clientPath exists before chdir

Submitting patches back to p4 requires a p4 "client".  This
is a mapping from server depot paths into a local directory.
The directory need not exist or be populated with files; only
the mapping on the server is required.  When there is no
directory, make git-p4 automatically create it.

[ reword description --pw ]

Signed-off-by: Gary Gibbons <53167360c0a5a27865f3be72f4d909e96b8e5ee7@perforce.com>
Signed-off-by: Pete Wyckoff <1a91d62f7ca67399625a4368a6ab5d4a3baa6073@padd.com>
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