This patch implements llMessageLinked.
I had to make a change to llGetLinkNumber to return m_host.LinkNum + 1 for
link sets of more than 1 prim, or 0 for a single object, since according
to:
http://rpgstats.com/wiki/index.php?title=LlMessageLinked
linksets with 2 or more prims start the link numbering at 1, but a single
prims link number is 0.
In his own words:
If a prim becomes a listener or remote channel and the script is deleted, it cannot become a listener or channel again with a new script.
This patch fixes that.
