Make string escaping more like python wrt '\'.

TPolzer · TPolzer · commit 495777283793 · 2018-11-16T23:25:25.000+01:00
diff --git a/checktestdata.g4 b/checktestdata.g4
@@ -2,7 +2,7 @@ grammar checktestdata;
 
 COMMENT : '#' (~'\n')*'\n' -> skip;
 STRING_LITERAL : '"' CHAR* '"';
-fragment CHAR : ~["\\] | ESCAPED_CHAR;
+fragment CHAR : ESCAPED_CHAR | ~["];
 fragment ESCAPED_CHAR :
 	'\\"' 
 	| '\\\\' 
