The Witness Puzzles v1.0.9

Changelog:

• Add a way to enter seed number for the panel generator
  • Seed of a panel is displayed at the top of the screen
  • Here's a couple of good seeds to check out: 556287781 and 040665612
• Fix jittery / laggy line movements after resizing game window in desktop version (#13)
• Fix for subtractive tetris rule not working correctly in some situations (#14, #15)
• Miscellaneous minor fixes and improvements