A landmark bill to tax and regulate marijuana, authored by Assemblyman Tom Ammiano (D-San Francisco), was reintroduced in the California legislature today. The proposal would make personal possession and cultivation of marijuana legal for adults over 21 and would institute a regulatory system for marijuana sales modeled after the one that already exists for alcoholic beverages. Asm. Ammiano’s 2009 marijuana reform bill, A.B. 390, was approved in the Assembly Public Safety Committee last month but…