Merge pull request #3 from Junkern/master

Added Cassandra implementation for addColumn and addNamespace
Implemented programmatic conditional clause in hypertable
Merge branch 'master' of https://github.com/B3nRa/ColumnStoreUnifier
Merge pull request #4 from Junkern/master

Cassandra libs
Added functionality for conditional operator in "ScanTable" of HyperTableQueryHandler.
Multiple filters with the same attribute name can now be used for scanning a table.
Merge branch 'master' of https://github.com/B3nRa/ColumnStoreUnifier
Implemented ComparisonOperatorMapper to unify the comparison operator values used by different implementations. (e.g. < vs. LT, ...)
Added HBase. scanTable is still missing and all tests
Libs for HBase
Did some work on HBase scanTable. Some things to discuss about