Make mediawiki.action.view.dblClickEdit recheck preference

There's a preference which makes the browser go to action=edit when double
clicking on the content. In VE we want to disable this while the editor is
open. With this check in place, we can turn it off by falsifying the value
of the preference (and then restoring the original value when VE closes).

Bug: 53058
Change-Id: I0f6225b25ad279755548361f82b855727758da2b
Merge "Make mediawiki.action.view.dblClickEdit recheck preference"