These regulations shall not be construed as abating any action now pending under or by virtue of prior existing subdivision regulations or as discontinuing, abating, modifying or altering any penalty accruing or about to accrue or as affecting the liability of any person, firm or corporation or as waiving any right of the town under any section or provision existing at the time of adoption of these regulations or as vacating or annulling any rights obtained by any person, firm or corporation by lawful action of the town except as shall be expressly provided for in these regulations.