webaccess: Log all authentication successes/failures
webaccess: Log all authentication successes/failures

This loses some of the granularity of the default HTTP basic auth
(unknown username vs. bad password), but there is considerable value
in having logging that is consistent no matter what authentication
plugins are installed.

storytouch/etherpad-lite,ether/etherpad-lite,storytouch/etherpad-lite,ether/etherpad-lite,storytouch/etherpad-lite,ether/etherpad-lite