Improving Paint application

1. App lets you choose any color using ColorChooser
2. Images can be saved (for now only with hard coded path)
3. You can clear the screen and start drawing again
4. by scrolling mouse wheel the stroke size changes, totally sync with
the text field. By scrolling the wheel text field updates and by
changing the number in the field stroke changes also (No need to press
Enter after changing value in the text field, it picked up immediately)