Registers a new tag type for the use with GStreamer's type system.
Same as Tag.register, but name, nick, and blurb must be static strings or inlined strings, as they will not be copied. (GStreamer plugins will be made resident once loaded, so this function can be used even from dynamically loaded plugins.)
the name or identifier string (string constant)
a flag describing the type of tag info
the type this data is in
human-readable name or short description (string constant)
a human-readable description for this tag (string constant)
function for merging multiple values of this tag, or NULL