Calendar rebase

This replaces #1281.

Fixed unit tests and cleaner history based on Scott's rebase. Unit tests work in latest FF and Chrome but still fail via grunt. @jzaefferer You mentioned an upcoming improvement for asycTests?
@tjvantoll I think your latest comment should be posted here: https://github.com/jquery/jquery-ui/pull/1316/files#r16630674

I've changed the test to check if additional classes are set and if the created element itself seems correct. Nothing more. 5 tests in total.