Set up dsh group under glance user and rsync in glance-image-sync as glance user
Change glance_image_sync group name to glance-image-sync
Change lock_file since glance can't write to /var/run
Chown glance-image-sync.log to glance:glance and lock to /var/lib/glance

Current installations run glance-image-sync as root, so we chown that file to
ensure we can run and log as glance user.  Also removing
/var/lock/glance-image-sync as we will create that directory in our OS package,
so for now we just lock to /var/lib/glance which already exists and is
writable by glance user.
Merge pull request #166 from mattt416/sync_as_glance_user

Merged automatically by jenkins after successful build test