Added second derivative to max downsampling function
Add c_init_code_apply().
Make GpuKernelBase use c_init_code_apply() and fix GpuEye to use the new API.
Allow string constants in kernel code to actually work.
c_code() for GpuCAReduce.

This is not pretty code, but it is working code.
Document c_init_code_apply().
Remove stray debugging print.
Return a proper version from c_cache_code_version().
Fix handling of shaped for 0-sized arrays.
GpuShape
Add tests for DownsampleFactorMaxGradGrad

- call verify_grad on DownsampleFactorMaxGrad
- call hessian on DownsampleFactorMax
small test speed up.
Merge pull request #1564 from Snarfza/downsampleGradGrad

Added second derivative to max downsampling function
Merge pull request #1657 from lamblin/downsampleGradGrad

Add tests for DownsampleFactorMaxGradGrad
Merge pull request #1646 from abergeron/c_red

c_code() for GpuCAReduce (in gpuarray)
Merge pull request #1653 from nouiz/gpushape

GpuShape
In RepeatOp, fix detection of numpy-supported dtypes
Merge pull request #1658 from lamblin/fix_repeatop_bitwidth

In RepeatOp, fix detection of numpy-supported dtypes