harvesthq/chosen — pull request #916 by stof (2012-11-28 23:38:19+00:00)
Title: Fixed the handling of ctrl key for multiple select

jQuery 1.7 is no longer emulating evt.metaKey based on evt.ctrlKey on
windows so the support of the ctrl key was not working anymore on windows.
And the Prototype version was also broken as this normalization was not
provided in this library.
Fixes #562

I allowed both the metaKey (not mapped on windows) and the ctrlKey on all platforms for simplicity.

@pfiller please review this.