Update internal tag

Update tag in configure.in and git tag to match.

Fix decimal 0 {value 0 scale 0}

The mp library's value for 0 was incompatible with Cassandra's varints, have to special case it when writing a decimal to cassandra.

Add duration type to casstcl

Add support for duration type.

Sync tag and configure.in

Update configure.in and tag to match.

Interact improvements and cleanup.

• Added some introspection commands to interact.
• Updated README.md to match API.
• Minor fixes.

Add -withnulls option to "cass select"

• cass select -withnulls SQL arrayName codeBlock

Support for Cassandra 2.2

• Support for new ttiny, small int, date and time ypes in Cassandra 2.2.
• added "whitelist_filtering" method to casstcl cassandra objects.
• Added "heartbeat_interval" method to casstcl cassandra objects.
• Added "metrics" method that returns a key-value list of metrics returned at the C level by cass_session_get_metrics.

v2.10

compatibility with cpp-driver 2.1.0