Changed submodule directory and changed way its linked,
in order to use target_link_libraries checkouted phmap
dependency to the newest revision which includes small
cmake fixes (see 031d214f2ce1973933abdf2a998d986ff8094d8e),
updated paths in PureCoverage script and Doxyfile
Add HTML and XML code coverage report generation with gcovr.
Cleanup unittests list - add missing googletest-gui to the unittests
list; remove dead functional tests.
Signed-off-by: Marcin Smoczyński <smoczynski.marcin@gmail.com>