Allow more fine-grained feature support listing #13
Description
Right now, one can only say that an implementation supportes a freature, or not. But one may want more fine-grained information (see also issue #7), e.g. to record this:
- An implementation might be client/server, but supports a feature only in client-mode, not server mode.
- The version in which a feature was added / removed.
- Track whether a feature is supported, but disabled / enabled by default