Added mobile support for WebGL version

I realized the game design works very well on mobile phones so I decided to add mobile support for changing the camera with a Two-finger touch.

There were also some minor changes:

• Support for changing camera on mobiles;
• Changed camera key to C (since Chrome opens its help on F1);
• Change the ground color of every level (Noticed some players didn't realize there were more than one level, this should be enough to make it more apparent);
• Kept and renamed Windows x64 version to match Compo submission.

Nothing has changed in gameplay.