Unfortunately it's not uncommon to be correlating mirror access logs
to remote requests to see what is going on with access failures. It
is *much* easier when everything is in ISO8601 format and not using
strings for month names, etc.
Switch the log format used everywhere to "compact ISO 8601 format,
including micro-seconds". The errorlog format is based on
http://httpd.apache.org/docs/2.4/mod/core.html#errorlogformat
Change-Id: I0aafb831d5c5ca3abf031771d5f59c986611e197