GFA Status Report

Finally some progress has been made on the old GFA-Basic Compiler.
- DIM crash fixed, issues an error message instead
- MAT INPUT crash fixed, issues an error message instead
- $U/$U+ error handling is more stable
- Added a real time line counter that is 040/060 safe, not interrupt driven
These will require a new library:
- MSHRINK() bug finally resolved
- MALLOC(), MFREE(), and MSHRINK(), moved into the lib, was hard coded
- FSNEXT(), FGETDTA(), and FSETDTA() moved into the lib, was hard coded