Some movies lend themselves to reviewing, and some don’t. Last week’s “Lockout” was a straightforward flick to write up. “The Cabin in the Woods” is anything but — it has a very specific, narrow audience and you’re either in it or you’re not. If you are, you probably know it already and saw the flick the day it opened. If you aren’t, then you don’t really need me to tell you to avoid it.