Use System.nanoTime() for timeout calculation

This fixes #150.
Typo in error message fixed
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
Merge branch 'nanotime-lock' of https://github.com/ash2k/astyanax into ash2k-nanotime-lock
Merge pull request #482 from sagarl/ash2k-nanotime-lock

Making timeouts more precise in ColumnPrefixDistributedRowLock
issue 384 fix
Merge pull request #485 from opuneet/issue384fix

issue 384 fix
fix for issue 457
Merge pull request #487 from opuneet/issue457

fix for issue 457
Merge pull request #467 from mkmainali/ISSUE-466

ISSUE 466 fix pull request
adding thread safety guidance
Merge pull request #488 from opuneet/issue27

adding thread safety guidance
adding createKeyspaceIfNotExists()
adding unit test for issue 382 fix
Merge pull request #489 from opuneet/issue382

adding createKeyspaceIfNotExists()
Make compatible with Guava 16.0.