preparing for fullscreen button

- removed "<header><h4>Controls</h4></header>" to save space for new button
- added fullscreen button
updated grayscott.js to handle fullscreenbutton

- taking canvas size from DOM element, not hardcoded
- make mouse movements scroll-aware
- add click handler for fullscreen button
Merge branch 'patch-1' of git://github.com/grundguetiger/jsexp into grundguetiger
Fullscreen mode

- Some fixes to fullscreen implementation
- JQuery UI buttons
- Light and fast resize of canvas