We don't mean to brag or nuthin', but we're usually pretty good at knowing what's going on around downtown, development-wise. It's our job, more or less. So it's a fun little change of pace when something big is going down and we have no idea why -- finally, the thrill of the unknown! That's the case this week over in Old West Austin near downtown, where a major demolition is now planned for a roughly 1.2-acre assembly of adjacent . . .