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

src/asm/lexer.c

@@ -1722,12 +1722,6 @@ static size_t appendStringLiteral(size_t i)
 				c = '\\';
 				break;
 
-			case ',': // `\,` inside a macro arg string literal
-				warning(WARNING_OBSOLETE,
-					"`\\,` is deprecated inside strings\n");
-				shiftChar();
-				break;
-
 			default:
 				error("Illegal character escape %s\n", printChar(c));
 				shiftChar();