Much improved error messages for ca65. For most errors it will now say what

was expected and what was found instead. Also improved error recovery in a few
places.

src/ca65/easw16.c

@@ -96,7 +96,7 @@ void GetSweet16EA (EffAddr* A)
             /* Register number */
             A->Reg = (unsigned) Reg;
         } else {
-            ErrorSkip ("Register or register number expected");
+            ErrorExpect ("Expected register or register number");
             A->Reg = 0;
         }