Remove deprecated RGBASM features (#1215)

- Escaped commas "\," inside strings
- `name: MACRO` syntax
- `__FILE__` and `__LINE__`
- `-H/--nop-after-halt` and `-l/--auto-ldh` on by default

test/link/all-instructions.asm

@@ -242,6 +242,7 @@ jrlabel:
     ei
     halt
     nop
+    nop
     scf
     stop
 FOR BYTE, 256