Update docs for Y.UA.os

From what I could read in the code more OSes were already supported.
Merge remote-tracking branch 'customcommander/update-docs-ua-os' into live-docs
Merge branch 'live-docs' into dev-master
[yui] Build
Merge branch 'dev-master' into dev-3.x

Conflicts:
	build/yui-base/yui-base-coverage.js
	build/yui-core/yui-core-coverage.js
	build/yui-nodejs/yui-nodejs-coverage.js
	build/yui/yui-coverage.js