Merge optimizer 5319

Add C code for CPU and GPU for tensor.Split op.

Fix gpu integers in scan.

validate numpy1.12 compatibility changes

casting to int could lead to issues in the following case:
- 64-bit Windows
- python 2
- shape bigger than 2**31

In that case, int would be 32-bit, but shapes could be bigger and stored
in long.

Fix CAReduce.c_code_cache_version_apply
Calling `append` on a tuple raised AttributeError, which was mistaken
for a missing `c_code...` function altogether, and the version was
ignored.

Done in both CPU and GPU code.

Speed up one scan opt

Mixed

Typo in sharedvalue.py

* Added missing softsign import

* Update __init__.py

+ some other code updates.

clarify error message.

Update. The GPU code does not more use `GpuArray_move` as this function seems to be too slow when copied data are not contiguous.

Now basic views are created and a view_map is declared for the op (on GPU only).

set jenkins PR c_cache TTL to 7 days