Added the unit test suite

* Using cmake to do builds
* Using google test for unit testing
* Unit test files go under test/unit
Added build and test instructions to the README
Added format rules to the project
Added cxxdbc::Connection

* Also had to add a make_unique implementation until C++14 support
is more mature
Added cxxdbc::Blob

* Represents a type-erased data blob
* Has its own pointer-based iterators
Added cxxdbc::Statement
Added cxxdbc::ResultSet
Added cxxdbc::ResultSetMetaData
Added cxxdbc::Type
Added cxxdbc::ResultSetMetaData::isNullable
Added cxxdbc::Exception
Merge branch 'vocab_types'

* Created a rough project structure
* Added first passes at various vocabulary types, inspired by
corresponding JDBC types