bind feature in DAV header

It seems to me that the BIND spec does not introduce a "bind" feature
to be reported in the DAV header of an OPTIONS response.

I think this should be added for the following reasons:

The feature list in the DAV header is useful for clients in deciding
which PROPFINDs need to be done in order to discover all that
is to know (= live properties) of a resource.

The nice thing about the DAV header is that a client can expect
this header to be rather static during the lifetime of a session.
In contrast, the supported-live-property-set can change quite
dramatically during the lifetime of a resource.

If a PROPFIND on DAV:resource-id will yield a meaningful response
cannot be deducted from the Allow header, since on non-collection
resources the BIND method will not be reported there.

//Stefan