Use CMake as a build engine

[sashafrey]

CMake should save us a lot of troubles. We already have many issues with our current build system:

• Current Makefiles doesn't work well in Fedora because it uses /etc/ld.so.conf to load .so dependencies (while Ubuntu uses LD_LIBRARY_PATH).
• Currently we maintain Makefiles and Visual Studio project files. CMake is able to generate both Makefiles and VisualStudio project files based on CMakeLists.txt.
• https://github.com/sashafrey/topicmod/issues/47
• https://github.com/sashafrey/topicmod/issues/45
• https://github.com/sashafrey/topicmod/issues/6

[sashafrey]

Already done and integrated into master