Use Go 1.3 http.Server.ConnState for graceful stop.

This can finally preempt idle keepalive connections.
Use SetKeepAlivesEnabled.
s/waitGroup/wg/
Merge branch 'master' into go1.3. The go1.3 branch at https://github.com/rcrowley/go-tigertonic as of 25july2014 becomes the master branch of https://github.com/glycerine/go-tigertonic/