Don't make TopoOptimizer profile the validate time as this is not needed.

This lower memory usage and speed up optimization by asking for less merge.

This make Merge Optimzer take 21s instead of 35s in one case.

I think this work correctly in case of revert.

[MRG]Deprecated

The NULL check was there before 4b4eeaad

Skip a test with python 2.4

Manually updated scan c code version too.

This simplify the *IncSubtensor code at the same time.

IncSugtensor and the GPU code still need update.