Revert "Use pacemaker to run neutron l3 agent and metadata agent"

This reverts commit 9ae3c52104a2098b2566fe77e5420ec93b5875f7.

There are three issues:
 - it doesn't work on Ubuntu
 - upgrading the images on a cloud with old heat templates will 
   fail (needed to permit upgrading heat to transition to HOT)
 - upgrading an existing a/a cloud will cause 2/3rds of the 
   networks to stop routing until their networks are rescheduled. 

We need to fix all three things before landing this.

Change-Id: I92818ef4324493f19207c10a73a0d6510795e9cc
Merge "Revert "Use pacemaker to run neutron l3 agent and metadata agent""