Update README.md
Screen y 0 should be at the top of the screen, not the bottom
Removing some trailing whitespace
Making 0 the top of the screen.
Add Proximity-Alert to extras
Merge branch 'master' into node

Conflicts:
	README_DOCS.md
	docs/extras/leapjs-plugins-0.1.0-extras.js
	docs/main/leapjs-plugins-0.1.0.js
	extras/leapjs-plugins-0.1.1-extras.min.js
	main/leapjs-plugins-0.1.0.min.js