Fix EZP-20572: Image editor stopped working after jQuery update to 1.9.1

JIRA issue: https://jira.ez.no/browse/EZP-20572

Description
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The update to jQuery 1.9.1 broke the image editor. Besides the issue with the `live` function mentioned in the JIRA issue, the Jcrop plugin also needs to be updated to be compatible with this new version, unfortunately, a lot of changes have been done to it and this update breaks several others features of the image editor...

That's why, I finally choose to add the [jQuery migrate plugin](https://github.com/jquery/jquery-migrate/#readme) which allows to upgrade to jQuery 1.9.1 seamlessly.

Tests
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Manual tests in IE8, IE9, Chrome and Firefox