Adding Doxygen support. Run `make doc` in your build directory!
Some cool doxygen features: TODO list!
FIX format warning for scanf when reading config (bool vs int)
Error checking in GParticleReconstruction::OpenCutFile()

*) Throw false in case file can't be opened
*) Use GetObject() instread of Get(). Provides type checks then loading objects.
*) Throw false if object can't be found inf file
Doc for GParticleReconstruction::OpenCutFile()
Terminate program if a cut can't be loaded

This avoids silently not including some particles in the output