git-patch-set: use HHMM time instead of HH:MM

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
git-patch-set: Create a new hook for doing stuff before patch sets

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
git-patch-set: add post-patch-set hook

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
git-patch-set: move the pre-patch-set hook invocation down

Only run it if we're sure we're going to create the directories, etc.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
git-patch-set: check for executable bit on hooks

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>