Switches Google search to verbatim, but allows you to turn it off later.
Switches Google search to verbatim iff the URL does not contain "source" or "sclient" parameters, which should allow you to turn off verbatim after searching if desired. Browser addons or userscripts that clean those parameters from your URL will break this functionality.
Credit to technicallyrite who wrote the original googleverbatimsearch which provided the skeleton for this script. Besides the above change, my script will also run at document-start rather than only after the site has fully loaded, preventing unnecessary reloading.
