added bugs/tasks
always add a sitemap.
ensure that the sitemap has mimetype text/html.
try to add the filename into the CHK to get a list of keys people can easily download. TODO: only use the basename, not the full name (could have slashes).
Give each CHK a filename, so it can be referenced in the list of keys more easily.
sitemgr: store the CHK names in the projects for backwards compatibility: Old files which did not change should not require a new upload when updating pyFreenet.