Switch http logging to new logging infrastructure

[itamarst]

Currently http uses its own, semi-broken hard-coded system.
The new system would generate log events, and then an
observer would log them, or create performance metrics
(publishable via resource?) and so on. A basic requirement
is to be able to have different log files for different
virtual hosts, in standard httpd format. Possibly this
should be extended to per-vhost logging of general messages
and errors.

[glyph]

your semi-brokenness :)

[itamarst]

Out to be done as part of refactor. In return I am willing to write docs for
logging if you assign an issue about it to me.

[jknight]

If someone tells me how to do this I may do it. Otherwise, itamar, perhaps you can do it for the new-
web branch?