Don't crash if replicate_on_write is null on a table

JAVA-254 #fixes
Make sure connections are returned to the right pool

JAVA-255 #fixes
Clarify javadoc
Fix connection leaks in exception code paths
particularly when server is under extreme high loads,
it may throw RuntimeException, and in these exception
code paths, opened connections has to be closed
before returning the control to the caller.
Add Session.prepareAsync

JAVA-224 #fixes
Add logged keyspace getter in Session

JAVA-249 #fixes
User date string in query builder to workaround CASSANDRA-6718
Merge pull request #155 from shaochuan/1.0-leak-fix

Fix connection leaks in exception code paths
Don't do post-prepare phase on I/O thread
Always return the PrepararedStatement object that is cached internally

JAVA-263 #fixes
Fix race when multiple connect are done in parallel

JAVA-261 #fixes
Better javadoc
Don't connect to nodes that are ignored by the load balancing policy

JAVA-270 #fixes
Fix a stackoverflow in Cluster init
Actually set the scale in LatencyAwarePolicy.Builder#withScale

JAVA-275 #fixes
Update dependencies
[maven-release-plugin] prepare release 1.0.6
[maven-release-plugin] prepare for next development iteration
Update READMEs
Add methods to check if a cluster/session instance if closed

JAVA-114 #fixes