Bug 1088561 - Enhance testAddons_pluginDisabledAfterRestart to check that if plugins work when enabled. r=aeftimie, r=amatei

--HG--
branch : mozilla-aurora
rename : firefox/tests/functional/restartTests/testAddons_pluginDisabledAfterRestart/test1.js => firefox/tests/functional/testAddons/testPluginInDifferentStates.js
extra : transplant_source : %8A%A9%0E%D6%1F%F4x%1D%1C%F3%85_%C3%DD%C2N2%ED%23%F2