Move ENABLED_SERVICES to stackrc.

allow us to do things like that :

ENABLED_SERVICES="$ENABLED_SERVICES,swift"

in localrc instead of having to copy the full config from stack.sh.

Fixes bug 951598.

Change-Id: I17e168473540760bcfa40a752ff2c266bd9b7044
diff --git a/stack.sh b/stack.sh
index 991ea00..2c535b9 100755
--- a/stack.sh
+++ b/stack.sh
@@ -83,7 +83,8 @@
 # If ``localrc`` exists, then ``stackrc`` will load those settings.  This is
 # useful for changing a branch or repository to test other versions.  Also you
 # can store your other settings like **MYSQL_PASSWORD** or **ADMIN_PASSWORD** instead
-# of letting devstack generate random ones for you.
+# of letting devstack generate random ones for you. You can customize
+# which services to install as well in your localrc.
 source ./stackrc
 
 # Destination path for installation ``DEST``
@@ -181,9 +182,6 @@
 # Melange MAC Address Range
 M_MAC_RANGE=${M_MAC_RANGE:-FE-EE-DD-00-00-00/24}
 
-# Specify which services to launch.  These generally correspond to screen tabs
-ENABLED_SERVICES=${ENABLED_SERVICES:-g-api,g-reg,key,n-api,n-crt,n-obj,n-cpu,n-net,n-vol,n-sch,n-novnc,n-xvnc,n-cauth,horizon,mysql,rabbit}
-
 # Name of the lvm volume group to use/create for iscsi volumes
 VOLUME_GROUP=${VOLUME_GROUP:-nova-volumes}
 VOLUME_NAME_PREFIX=${VOLUME_NAME_PREFIX:-volume-}