figure out what to do about the ETag headers apache is sending down.

fix up the strcmps for "entry" and "modified", they're a little off, should
also compare namespaces, just in case...

might be nice to switch to a parser that would let us write data out to the
wire as we parse it, instead of having to wait until after we've parsed the
entire file and removed the unneeded entries before we can send any data to
the client.

support other rfc3229 IM methods, diffe would be pretty simple, for example.

have a way to limit this filter to files in a particular directory.