AdvancedSubtensor1(AdvancedIncSubtensor1(0s, y, idx), idx) -> y
AdvancedSubtensor1(AdvancedSetSubtensor1(x, y, idx), idx) -> y

gh-2246

TODO: doc the new tag

Fixes a crash of casting bytes to Python string

The crash happened when cuDNN isn't used and the error message was raised. However, the message was a 'bytes' object, not a string. Casting the bytes to string solves the issue.

Fix ifelse crash and gpu support

fix gh-2262. Fix crash cause by using cudnn when we shouldn't

Support GpuCumsum on 3D array.

Slightly clean up registration of GPU convolution optimizers

Documentation for sliding windows 

Cache opt

Fix cuDNN detection

Add CUDA include dir so cuda.h is found; also add CUDA library dir to mimic configuration when compiling CUDA ops

Roy xue fix crash and gpu support