Fix EZP-21005: When changing siteaccess, the autosave's preview is not updated

# Description

This issue affects Chrome on Mac, this is the results of this bug: http://code.google.com/p/chromium/issues/detail?id=36518

To detect a siteaccess change, the change
event is now used on the select, but in IE < 9, the change event does not
bubbled, as a result, this fix also removes the usage of event delegation to
not break this feature in IE.

# Tests

Manual tests in Chrome (Mac, Window and Linux), Firefox (Windows and Linux), IE 8 and 9