Before running the simulation, check if necessary arrays are copied to GPU

[esinyavuz]

Before running the simulation, check if necessary arrays are copied to GPU

[esinyavuz]

One way of doing this could be to add a "sanity check" function in runner.cc which would go through the list of all the neuron and synapse groups, copy their variables from the device, print the first values, and sum of absolute values, and return a warning if this sum is zero. Users can then call this function before calling the kernels if they wish. It should be easy enough to implement.

[tnowotny]

This has been overtaken by history.