Remove macro both for FFTW mangling and factorized loops

I propose a way to remove the macro in the code.

It is just a proposal, @clalescu could you have a look and decide if it should be merged (in develop)?

But I feel it can help to develop.

Thanks.

mentioned in commit 32c0da97

Status changed to merged

This looks good, @bbramas. Hopefully it won't require too many changes to bfps_addons... I guess I'll see that along the way.

Best, Chichi L

Ok, I tried to adapt my style to the project, but do not hesitate to tell me if I miss something.