Merge Ionization into Dev to see changes

The code is compiling but once I try to run it, I am receiving a SegFault without much other comment. 
That happens when I use CUDA 5.5 or 6.0. If I use 6.5 it tells me that it cannot find a CUDA capable device.
` float3_X electronMomentum (parentIon[momentum_]*(massElectron/massIon))`
is the same and more readable