Last night, Mission Gardens at 1880 Mission St., a six-story building approved just about four years ago, got another entitlement extension — a two-year one, through October 2011. It's tough times for developer Avant Housing, who acquired it from the former developer Armax. During the Planning Commission's meeting, the 194-condo project was called an "interesting commentary on San Francisco's development process." To wit, the the ball first got rolling on Mission Gardens way back in 1999. Ten years later, and it now has a two-year extension. But the people behind Mission Gardens are still gung ho about it, and so is the Planning Commission. One of its more notable features: a 20 percent of the units will be affordable.