Note that they're all copied "flatly" into the toplevel web directory.
There is no problem with overwriting, since if a resource file is
rendered twice the renderer will throw an error. There shouldn't be too
many chances for such clashes since each kind of resource has a unique
suffix, but if this happens it's easy to change `copydir/flat' to copy
files using their paths, or something similar (like copying "x/y.z" to
"x-y.z"). In that case references to these resources should change too.
Also move the logo and favicon files to that directory instead of
copying them individually.
