Disabling FireQuery requires to restart Firefox (though it's restartless)

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To reproduce:

• in a clean Nightly x64 2015-11-03 profile (win10x64), with only fireQuery installed (this latest test build)
• open the jQuery Test page
• open DevTools(Ctrl+Shift+I) and click the Console tab
• press the Log data button:
  You'll see that two new entries with a little envelope in Console .
  You can inspect the data by clicking on the envelope icon. Also notice the jQuerify button.
  Now close DevTools
• now open about:addons in a new tab and disable fireQuery.
• open DevTools again and click the Log data button:
  you'll see that the new entries still have the envelope icons, and that the jQuerify button is still there.

You must restart Firefox for fireQuery to be disabled.

_Enabling it from disabled state applies immediately though (after closing and re-opening DevTools)._