USER: Added new functionality to perform charged particle and meson reconstruction over specific theta region only! Useful for the eta group, otherwise shouldn't *really* be used...
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
Tree production in physics class

Added first portion of tree production in physics class. This will be done ahead of histograms.
Improved tree handling in Pi0 physics class.

A two stage physics analysis is now implemented in the example PPi0 class. A basic tree is created containing only the calculated Missing Mass and Energy, along with the TC, incident photon energy, theta, phi and time for timing cuts. Histograms can be produced from this tree (at the same time) without interfering with the tree. This is done so that the histogram binning can be changed on the fly (as well as missing mass cuts and prompt/random timing cuts). All controls are still hard coded into the init section, however this will change to be user controlled (either via command line flags, or through a config file).