Deploy Apache as web front-end for gluster-swift

Swift can alternatively be configured to work as a request processor of
Apache server. This alternative deployment scenario uses mod_wsgi of
Apache to forward requests to the swift wsgi application and middleware.

'client' <---> 'Apache2+mod_wsgi' <---> 'middleware' <---> 'core swift'

Change-Id: If396dcbdf651af0dce55b951cd2eaadc6783384f
Signed-off-by: Prashanth Pai <ppai@redhat.com>
Reviewed-on: http://review.gluster.org/6116
Reviewed-by: Luis Pabon <lpabon@redhat.com>
Tested-by: Luis Pabon <lpabon@redhat.com>