Check for null when looking up persisted ConfigKey
Minor changes to help downstream Riak project
This closes #327
Adds MultimapSerializer

Should eventually be replaced with the Guava serialisers in the
jackson-datatype-guava module.
Fix DNS entity reverse lookup domain
Catalog item comparator - implement custom

The NaturalOrderComparator leads to unexpected sort order (i.e 0.0.0_SNAPSHOT and 0.0.1-SNAPSHOT-20141111114709760). OSGi's Version class and other semver java implementations are too strict.
Fix NPE on creating entities with no explicit location
This closes #314
This closes #329
This closes #331
catalog js-gui tweaks

* force server ordering to be respected on refresh, so new default versions show at root
* update applications as well as entities
* fix bug where sometimes on relead, policies would cause errors in browser
allow region and endpoint specified as explicit keys to override ones set implicitly