Fix Save and Load x2 problems

### Hi
Hello everyone, i am mahdibot . a scratcher, i realized this that scratch can't save a file and must do **Save as** which is not good . and when you load of your computer two times . typing in all text fields get disabled 
**I HATE JAVASCRIPT** but i'm working to solve this problem
i will be happy if somebody fix it . 

**This is for all repos like scratch-gui and scratch-vm **