Throws NPE on null in addContactPoint (JAVA-291)
Properly close unused connection
Don't mark node suspected at initialization and other cleanups
Avoid LoadBalancingPolicy onDown+onUp at startup (JAVA-315).
Limit unecessary work on startup
Fix unit test
Merge branch '2.0' into 2.1

Conflicts:
	driver-core/src/main/java/com/datastax/driver/core/ControlConnection.java