stash: implement "stash create"
stash: implement "stash create"

This subcommand creates a stash from the current state and writes out the
resulting commit object ID to the standard output, without updating the
stash ref nor resetting the tree.  It is intended to be used by scripts
to temporarily rewind the working tree to a clean state.

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