- delete.c: added more destructor functions

- deallocate all our data structures on exit (to help find memory leaks, bad
  pointers, and general logic errors)
- fixed memory leak when allocating pad names in instantiation
- added "magic" environment variable FPED_NO_GUI to run fped without 
  initializing Gtk+
- added valgrind wrapper "leakcheck"
- delete.c: destroy() now requires a deletion to exist
- vacate_op: free string expressions
- destroy_obj: free measurement labels
- delete_references: use do_delete_obj so the we don't bump the group number
- delete_frame: delete references after deleting the frame itself, so they end
  up on the stack above the frame and get destroyed first
- do_delete_vec: like above, even though it doesn't matter here



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5506 99fdad57-331a-0410-800a-d7fa5415bdb3

expr.c

@@ -459,9 +459,12 @@ struct expr *parse_expr(const char *s)
 
 static void vacate_op(struct expr *expr)
 {
-	if (expr->op == op_num || expr->op == op_string ||
-	    expr->op == op_var)
+	if (expr->op == op_num || expr->op == op_var)
 		return;
+	if (expr->op == op_string) {
+		free(expr->u.str);
+		return;
+	}
 	if (expr->op == op_minus) {
 		free_expr(expr->u.op.a);
 		return;