Remove `R return` macro

[codereport]

In j.h on line 888, there is a macro defined for return:

#define R               return

This should be removed and all instances of R replaced with return.

Note: there are ~4000 references to this, so some regex expression like [^a-zA-Z]R will need to be used to find and replace

[juntuu]

I actually had this already done locally. I'll double check it and add a PR.

[codereport]

I actually had this already done locally. I'll double check it and add a PR.

Awesome! Looking forward to seeing the PR