ENH: minor -- print time which was used to process lines

Actually thought to check empirically if increasing re._MAXCACHE to e.g. 10000  (as have heard during pycon14) would have an effect while parsing large files... in my attempt on apache log and apache-badbots -- no effect whatsoever (thus not committed).  But it might just need better check  and this little PR is just to spit out what time the actual loop for parsing lines took.