Remove specific timing from FAQ.
Remove specific timing from FAQ.

I'm not convinced I was measuring the overhead of sandwich accurately,
plus the existing argument was weak: it's not 1000ns total overhead, it's
1000ns per middleware step.  An app that has ~20 middleware steps will
suffer ~20usec call overhead... if my numbers were correct in the first
place.

Anyways:
TODO(aroman): Accurately measure timing overhead.

augustoroman/sandwich