Add CQL support for more types, add test cases, edit README.

Add support for CQL3 types: ascii, bigint, boolean, decimal, double, float,
int, varint.  Add partial support for types text and varchar.

README.md improved to include a short example of CQL3 statements.
Add support and tests for retrieving CQL3 collection types.
Merge pull request #12 from Lanzaa/basic-cql3-01

Support CQL3 Collections and other types