fix test following the removing of set_flops.
Merge pull request #1573 from nouiz/fix_test

fix test following the removing of set_flops.
Fix pickling of GpuConv op due to not completly removing set_flops last time.
Minor typo fixes and rephrasing for clarity
Merge pull request #1575 from delallea/minor

Minor typo fixes and rephrasing for clarity
Merge pull request #1574 from nouiz/fix_test

Fix pickling of GpuConv
Add acknowledgement about the MRG31k3p implementation.
fix typo followint code review.
Merge pull request #1577 from nouiz/ack

Add acknowledgement about the MRG31k3p implementation.
Add profiling detail for the MergeOptimizer
Fix comment.
make opt faster by using in2out instead of equilibrium.
pep8
Faster fgraph change during opt.

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

I think this work correctly in case of revert.
Make a cache for TensorConstant.

This lower memory usage and speed up optimization by asking for less merge.
Add profilingof TopoOptimizer (reused by in2out, out2in)
Make SeqOpt profile the validate time for each sub opt and the global callback time.

Don't make TopoOptimizer profile the validate time as this is not needed.
pep8 and change opt name.
Fix the constant cache during compilation.