Includes following changes:
0230d0698e59 add initial GitLab CI support
5e13b797a988 iron out all extra compiler warnings
802fbd4d6f39 cmake: enable extra compiler checks
050bb5c4431b convert into CMake project
5b350e42d1fd refactor into separate Git project
and converts the package build to utilize CMake.
Signed-off-by: Petr Štetiar <ynezz@true.cz>