LJ::accept_comm_invite — Accepts an invitation a user has received. This does all the work to make the
LJ::accept_comm_invite(uuserid, cuserid);
uuserid. a userid or u object of the user to get pending invites for
cuserid. a userid or u object of the community to reject the invitation from
cgi-bin/communitylib.pl
1 for success, undef if failure