Keystone support deploy in uwsgi

Keystone is going to remove support for eventlet. Rather than only
have one way to run keystone (in Apache Httpd with mod_wsgi), we
should continue to gate on multiple wsgi containers to ensure that
keystone remains container-agnostic. The suggested alternative
container is uwsgi.

To run keystone in uwsgi rather than httpd or eventlet, set the
following env var in local.conf:

 KEYSTONE_DEPLOY=uwsgi

There's a lot of options to uwsgi. Here's some protips:
http://uwsgi-docs.readthedocs.org/en/latest/ThingsToKnow.html

Change-Id: If3b49879ce5181c16f0f0ab0db12fa55fe810a41
diff --git a/functions-common b/functions-common
index ff9bc0f..d6c3bdd 100644
--- a/functions-common
+++ b/functions-common
@@ -1428,14 +1428,17 @@
     local service=$1
     local command="$2"
     local group=$3
+    local subservice=$4
+
+    local name=${subservice:-$service}
 
     time_start "run_process"
     if is_service_enabled $service; then
         if [[ "$USE_SCREEN" = "True" ]]; then
-            screen_process "$service" "$command" "$group"
+            screen_process "$name" "$command" "$group"
         else
             # Spawn directly without screen
-            _run_process "$service" "$command" "$group" &
+            _run_process "$name" "$command" "$group" &
         fi
     fi
     time_stop "run_process"