* Added SensorConfig and DCDBPublicSensor classes as interface for dcdbconfig
* Fixed bugs and tested:
  --> CollectAgent fully working
  --> dcdbconfig fully working

* Bump cpp-driver to 2.0.1
* Create new SensorId header/source that takes over the logic
  previously found in SensorDataStore related to populating
  SensorId structs from MQTT topic strings and serializing
  them into Byte Arrays to be used as Cassandra Row Keys.

* Bumped Cassandra to 2.1.5
* Bumped cpp-driver to 2.0
* Eliminated cassandraBackend in favor of DCDBConnection

In the future, a DCDBConnection handles the low-level connection
to Cassandra. On top of an established DCDBConnection, you can
create a SensorDataStore object which gives you access to raw
sensor readings.

The IPMIPusher is now deamonized and hardened for IPMI errors. Config files now accept also sensor data at chassis level.

The tool now reacts to  BMC error states and IPMI disconnects, always keeping a stable up-and-running state.

Related to ticket #29.

Found some memory leaks in DCDBLib and fixed
a bug related to thread handling in CollectAgent.

Use the -r option to get raw values instead.