Put everything in /usr/local and allow that to be overridden to
a user-writable dir and not require sudo.
Also set the stx-devstack-update job voting, at this time it only runs
on devstack/* changes.
Change-Id: Ibb27af08e4eaa0ba82d737e1af438a992ec35bfb
Signed-off-by: Dean Troyer <dtroyer@gmail.com>