Instead of answering GETINFO requests about our geoip usage only after
running for 24 hours, this patch makes us answer GETINFO requests
immediately. We still round and quantize as before.
Implements bug2711.
Also, refactor the heck out of the bridge usage formatting code. No
longer should we need to do a generate-parse-and-regenerate cycle to
get the controller string, and that lets us simplify the code a lot.
