revert ebin_modules to include all beams minus extra_src

[tsloughter]

This change broke inclusion of modules that are built straight to beam files and have no .erl file in the src dirs for them.

I don't think the removal of beams that are built from extra src dirs is required though... I kept it there since I'm just reverting to the old functionality, but extra src dir beams aren't built to the ebin dir, so not sure why that is there. Unless we should be building extra src dir files to ebin instead of doing the annoying copying of source files.

[ferd]

We needed the extra dir files apart just because they strictly didn’t belong in the final releases. Aside from that that’s all there is to it I think

[tsloughter]

@ferd right but they also aren't in the ebin dir so shouldn't have to filter them.