Double click on plugin Icons Screen Lock

[Vinícius Krolow]

If you make a double click fastly on one plugin icon like the "links", the lock screen shows over the popup so we can not use the popup

I tested it in my current version and the nightly version in both that happened.

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By krst: TC:

1. open CKEditor
2. double click on any icon which shows dialog window (link, flash, image etc)
3. Window shows up, but is disabled, focus lost, (attached screen), mouse cursor is "busy"
4. to disable this state, user must reload page.

It happens only once per button. after page is reloaded, double click on the previously blocked action, works as desired.

[Krzysztof Studnik]

Doubleclick effect

[Alfonso Martínez de Lizarrondo]

dup of #6390