Words in any statute, charter or ordinance giving authority to 3 or more persons authorize a majority to act when the statute, charter or ordinance does not otherwise specify. Notwithstanding any law to the contrary, a vacancy on an elected or appointed body does not in itself impair the authority of the remaining members to act unless a statute, charter or ordinance expressly prohibits the body from acting during the period of any vacancy and does not in itself affect the validity of any action no matter when taken. [PL 2007, c. 396, §2 (NEW); PL 2007, c. 396, §4 (AFF).]