configuration options (and remove an unused one) to make this happen.
* build-and-deploy.conf
(general): Add 'www_root' and 'www_root_href' settings.
* build-and-deploy.py
(BUILD_LOG_FILENAME): New.
(do_build): Use BUILD_LOG_FILENAME instead of a hardcoded path.
(main): Read 'www_root' and 'www_root_href', and use that to
construct 'dst_path' (no longer read from configuration) and the URL
to the build log.
