better CMake integration

[spirosmaggioros]

Each folder should have a CMakeLists txt and then integrate them to the main CMakeLists.txt in root dir.

[CharlesGueunet]

Using cmake libraires so other CMake project can request components seems the way to go. Having several CMakeLists.txt maybe nice, one per independent sub-projects, like the library, the plugins, ... Inside the library, you may want to have components that can be enabled disabled.

In any case, I would suggest to avoid GLOB completely as this is only evaluated at configure time, so any further changes but developers for example would be omitted.

[spirosmaggioros]

This is closed as CMake integration is fine for now