Like Rust's Proc macros. Now we have preprocessor recursion to worry about. I also made a cool macro for enums
About to move them completely to stdlib
- Atoms now use MFBI to distinguish between thin and owned atoms. - Introduced TryFromExpr and ToExpr (formerly ToClause) from the old FFI - Standardized on Bottom being a ProjErr, which means that there will be no RTErr
