Added unit-test source directory

Also includes a dummy test.
Added configuration of unit-tests
Made inclusion of the Boost unit-test framework conditional
Added generation of coverage data if testing is enabled
Changed to use tagged Boost libraries

Also commented out the coverage flag test.
Added the Turtle mocking framework

See http://turtle.sourceforge.net/ for details
Added the Turtle mocking framework

See http://turtle.sourceforge.net/ for details

Note that this is mostly for future use, as mocking is not needed right now.
Merge branch 'feature/unit-testing-setup' of github.com:pileon/raven-server into feature/unit-testing-setup
Updated ddummy test to use fixtures and test suites
Minor change if CMAKE_HOME_DIRECTORY doesn't exist
Comments update

Changed the filename in the header-comment
Added explanatory comments about some things
Addes test to make sure that cwd is not null
Removed unused header file inclusion
When checking for Boost, don't need the tags
Merge branch 'feature/unit-testing-setup' into develop