cheatsheet: add program version to header
cheatsheet: fix footer alignment (and remove dirty CSS hack)
cheatsheet: move GitHub links from footer to Links section
cheatsheet: add "Edit me on GitHub" link in footer
cheatsheet: clean up whitespace and indentation
cheatsheet: fix current stable version
Merge branch 'feature/cheatsheet/rework-header-and-footer' of git://github.com/rohieb/openscad.github.com

Conflicts:
	cheatsheet/index.html