Use System.nanoTime() for timeout calculation

This fixes #150.
Upgrading to io.netty-3.6.6.Final. Also fixing some unit tests
Merge pull request #462 from opuneet/issue461

Upgrading to io.netty-3.6.6.Final. Also fixing some unit tests
[Gradle Release Plugin] - pre tag commit:  '1.56.46'.
[Gradle Release Plugin] - new version commit:  '1.56.47-SNAPSHOT'.
de-merging the pull request
adding back deprecated constructor
Merge pull request #463 from opuneet/issue421revisited

adding back deprecated constructor
[Gradle Release Plugin] - pre tag commit:  '1.56.47'.
[Gradle Release Plugin] - new version commit:  '1.56.48-SNAPSHOT'.
Typo in error message fixed
fixing interface break constructor change
Merge pull request #465 from opuneet/issue421fix

fixing interface break constructor change
[Gradle Release Plugin] - pre tag commit:  '1.56.48'.
[Gradle Release Plugin] - new version commit:  '1.56.49-SNAPSHOT'.
Changed keyspace and column family metatdata to be initialized inside the static block
Merge pull request #464 from Benky/master

Typo in error message fixed
Making EntityMapper Public & Providing a way to add specific Partitioner for DefaultEntityManager
Fixing code indentation
Merge pull request #478 from sagarl/a6xissues474_468

Making EntityMapper Public & Providing a way to add specific Partitioner for DefaultEntityManager