Convert keystone to use uwsgi with the proxy

This makes keystone use the proxy uwsgi module when running in uwsgi
mode. It also introduces a new stackrc variable which is WSGI_MODE
that we can use to control the conditionals in services that current
work with mod_wsgi.

Also update retry timeouts on proxy pass so that workers don't disable
their connections during polling for initial activity.

Change-Id: I46294fb24e3c23fa19fcfd7d6c9ee8a932354702
diff --git a/openrc b/openrc
index 483b5af..4cdb50e 100644
--- a/openrc
+++ b/openrc
@@ -73,8 +73,6 @@
 fi
 
 SERVICE_PROTOCOL=${SERVICE_PROTOCOL:-http}
-KEYSTONE_AUTH_PROTOCOL=${KEYSTONE_AUTH_PROTOCOL:-$SERVICE_PROTOCOL}
-KEYSTONE_AUTH_HOST=${KEYSTONE_AUTH_HOST:-$SERVICE_HOST}
 
 # Identity API version
 export OS_IDENTITY_API_VERSION=${IDENTITY_API_VERSION:-3}
@@ -84,7 +82,7 @@
 # the user/project has access to - including nova, glance, keystone, swift, ...
 # We currently recommend using the version 3 *identity api*.
 #
-export OS_AUTH_URL=$KEYSTONE_AUTH_PROTOCOL://$KEYSTONE_AUTH_HOST:5000/v${OS_IDENTITY_API_VERSION}
+export OS_AUTH_URL=$KEYSTONE_AUTH_URI
 
 # Currently, in order to use openstackclient with Identity API v3,
 # we need to set the domain which the user and project belong to.