Add CMake support

[tehKaiN]

Writing makefiles is a pain and having custom build environment is no way to go. We don't need another standards.

Having CMake build environment would bring Amiga coding to 21st century even more. Also, CMake is very flexible at including other libraries with CMakeLists.txt written for them. Also, it by default supports stuff like debug/release builds and allows passing build options to dependencies very easily. It is easily configured to keep track of changes in .h files so no more using make all.

The downside is that there is no Amiga port for CMake. Yet.