when calendar was embed in a long form or an popup, system will select wrong timeslot when users click on a timeslot to select it

[hungkoala]

The issue cause by function Selection.js::getBoundsForNode line top = rect.top + (document.body.scrollTop || 0) does not correct because document.body.scrollLeft return 0

The issue may be fixed by changing to:
top = rect.top + (window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0);

see http://stackoverflow.com/questions/3464876/javascript-get-window-x-y-position-for-scroll