Initial hookup of mongodb

- Can inject both the main DB and MongoClient seperately
- Created EventCurator that actions on an 'event' collection.

NOTE: Integration tests will be against a live DB due to the fact
that supporting in-memory test libraries for java mongodb do not
implement all features of the java driver.
Persist events via curator
Fixing style issues
Fix broken Event.getTimestamp()

Candlepin events store dates as long. Do the same for
a GB Event for the time being. Perhaps we can transform
this to an actual date later.
Test config properties used when creating mongo client and DB.
Merge branch 'master' into mongo-master

Conflicts:
	gutterball/src/main/java/org/candlepin/gutterball/guice/GutterballServletModule.java
	gutterball/src/main/java/org/candlepin/gutterball/receive/EventReceiver.java
Fixing issues caused by rebase with master

Conflicts:
	gutterball/src/main/java/org/candlepin/gutterball/receive/EventReceiver.java
User ConfigKey for gutterball config properties.
Merge branch 'master' into mongo-master
Merge pull request #649 from candlepin/mstead/gutterball-mongodb

Add mongodb support to gutterball