Implement Meta-optimizer on new backend

(small fix) fix requirement-rtd

Move C files into c_code sub-folder in every module.

[BUG] Fix gh-6287 and a regression introduced in gh-6218

(small fix) use `os.remove` instead of system `rm` command

Prepare beta release 0.10.0beta1.

Make sure to pickle all attribute of Function (and FunctionMaker)

Alloc ops params

Use sha256 for config hash to be FIPS compliant and make Theano cache more forward compatible

Pickle/Unpickle trust_input. We use False (the default) for old pickle that don't have the information.

Fix missing scipy and warn that Theano will have a c++ compiler mandatory