Refactoring frontend / backends as extensions
Created originally on Bitbucket by paugier (Pierre Augier)
Refactor the code to split the analysis ("frontend") and the production and compilations of Pythran files (a Pythran backend). This backend should be written as an extension.
The long term goal would be to be able to use different Numpy accelerators (Pythran, Cython, Numba-CuPy, PyTorch) with the same Transonic code (we would have to change the name fluidpythran).
Writing backends as separated extensions would be very nice.
The user API may be adapted. We have to think about what the different backends would need.