move mongodb deployment into its own recipe
mongodb replica set support

Use the configure_replicaset library method from the
edelight/chef-mongodb repository by Markus Korn.
install rubygem-mongo immediately
define the mongodb subtree on nodes
use cluster founder as mongodb replica set controller
use pacemaker to handle mongodb service and ordering
clone the mongodb service in pacemaker
configure mongo for HA only if the use_mongodb attr is on
fix NoMethodError when mongodb is enabled without a cluster
restrict node searches to the current proposal
fix whitespace in warning log message
use admin network ip address when connecting to mongodb

also uses the admin ip address when defining mongodb replica sets

IP addresses should be more resilient e.g. when the DNS server is down.
always define mongo service with PacemakerService provider
add pacemaker sync markers for mongodb service
use the first instance node as the mongodb controller node
only establish pacemaker_order when use_mongodb is enabled
fallback if there are no replica set members

If crowbar hasn't set any mongodb replica set members, by using the
ceilometer_ha_mongodb_replica_set_member attribute, we just fall back to
using the first ceilometer-server node for the mongodb server.
make sure the ceilometer attribute subtree exists
Fix use of mongo gem after it got installed in this chef run
Cleanup search for mongodb node

We were not checking for the right environment, which might matter.