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.
Not at all :wink: 
There are two while loops, the outer one over the ion frames and the inner one infinitely. I already allow multiple ionizations in one time step. The ionization model sets the value of `newElectrons` for each thread. That quantity may very well be larger than 1 although it is often unlikely. During each cycle of the infinite loop each thread can only create 1 electron. As the electron frame may already be filled there are two creation steps. Then each thread counts down its `newElectrons` by 1. In the subsequent new cycle there may be some threads left with a nonzero number of `newElectrons` and so they get another round. Eventually all threads break out of the loop if `newElectrons` equals 0. Only then a new source ion frame will be worked upon.