Brace yourselves, fellow Mainers. We’re about to bear witness to the Battle of the Bongs. Wednesday’s announcement by Legalize Maine that it will soon begin circulating petitions for a citizens initiative referendum on legalizing marijuana in Maine was, in and of itself, an inevitable step forward in the nationwide movement to remove the penalties from possessing and partaking of pot. But here’s the rub: The Marijuana Policy Project, based in Washington, D.C., has been in Maine the past two years trying to do the same thing.