Add collection and data length checks during serialization (JAVA-363)

Patch contributed by @snazy.
Surface number of retries in metrics (JAVA-329).
Fix handling of null results from AddressTranslater.

The javadoc states that returning null should be the same as returning
the same address, until now it was ignoring the node.
Do not use a host when no rpc_address found for it (JAVA-428).
Update READMEs
Check cluster name when connecting to a new node (JAVA-397).
Add missing CAS delete support in QueryBuilder (JAVA-326).
Merge pull request #178 from olim7t/JAVA-326

JAVA-326: add support for conditional DELETEs in QueryBuilder
Add ResultSet.wasApplied() for conditional queries (JAVA-358).
Merge pull request #184 from olim7t/java358

Add ResultSet.wasApplied() for conditional queries (JAVA-358).
Add periodical cleanup of closed connections.
Check if connection should be forced when removing handler.
Fix negative HostConnectionPool open count (JAVA-349).
Update changelog for 2.0.6.
Improve ConnectionReaper + slightly raise interval.
Make some internal settings overridable in integration tests.
Log overridden internals at warn level.
Increase internal new node delay for tests.
Fix bug in JAVA-428 changes.
Merge branch '2.0' into 2.1