Added struct definition for photons
Added Photons class for basic organization of photons
Added a fixme
Cleaning up some old code
Added photons to Handler class
Added photon pusher
Added v2 for photons.

Realized that there are 3 velocity components for photons...
Implemented photon sorter
Implemented photon production
Added photon energy to struct definition
Integrated reflection into photon pusher
Added tile to photon struct
Changed photon sort to tile
Added tile partitioning for photons
Tweaked for some optimization on current deposition
Implemented photon counting
Fixed photon partitioner
Added erase chunk function for photons
Got rid of a debug message
Tweaked a bit single particle initial condition