SF bug #644345, Poor error message for augmented assign

Update error message.  Hopefully this is clearer to some people.

Python/compile.c

@@ -2778,7 +2778,7 @@ com_assign(struct compiling *c, node *n, int assigning, node *augn)
 				}
 				if (assigning > OP_APPLY) {
 					com_error(c, PyExc_SyntaxError,
-				  "augmented assign to tuple not possible");
+				  "augmented assign to tuple literal not possible");
 					return;
 				}
 				break;
@@ -2791,7 +2791,7 @@ com_assign(struct compiling *c, node *n, int assigning, node *augn)
 				}
 				if (assigning > OP_APPLY) {
 					com_error(c, PyExc_SyntaxError,
-				  "augmented assign to list not possible");
+				  "augmented assign to list literal not possible");
 					return;
 				}
 				if (NCH(n) > 1