Draft white papers on supplementary services H.450.4/5/6 uploaded

[Korpi Markku PN VS LP3]

I have uploaded the draft white papers on supplementary services to the
incoming directory of the avc-site.
These are
 - H.450.4 Call Hold
 - H.450.5 Call Park and Call Pickup
 - H.450.6 Call Waiting
and they can be proposed for determination in the SG-16 meeting in
September.

The fourth supplementary service, H.450.7 Message Waiting is also ready for
determination, but will be uploaded separately by Dave Walker.

--Markku