fixing neuralnetmnistconvolve
checking on backprop time
make possible to try different backprop functions, and compare
backprop for gpu for tanh written
transitioning to use gpu for backprop :-)
turned off non-gpu backprop, but error calculation for upstream layer still uses cpu
moved activation function to macro, rather than hardcoding in kernel
tidy up kernel a bit
working on migrate to gpu
upgrade OpenCLHelper
fix annoying bug
add runtests.sh, better than nothing...
merge conflict