Add initial styles for daterange markup
Don't import ; update less buildfile and css file
Don't import `.input-append .add-on`; update less buildfile and css file
Implement initial daterange picker
Merge latest master changes into range branch

--HG--
rename : build.less => build/build.less
Merge latest master into range branch
Merge latest master changes into range branch
add support for NO CONFLICT and DATA-API
add test for DATA-API, data-provide="datepicker"
Adding beforeShowDay function. Very similar to jquery datepicker beforeShowDay option at http://api.jqueryui.com/datepicker/#option-beforeShowDay
Bind to events only when the picker is shown.

Greatly increases performance on slow machines with IE8 when multiple
datepickers have been instantiated.
Fixes a memory leak.
Differentiate between main events (needed at picker init) and secondary events (only needed when picker is open)
Build event handler lists at init, not every time we attachEvents
Update bootstrap-datepicker.js
Update datepicker.css
Update datepicker.less
Update component.js
Update events.js
Update 2011.js
Update 2012.js