Support multiple VNC clients (Brian Kress)

Support multiple VNC clients (Brian Kress)

Change structure associated with a display from VncState to a new structure
VncDisplay. Remove client specific fields from VncDisplay. Remove display
specific fields from VncState. Maintain a linked list of VncStates per
VncDisplay structure, update as necessary. When updates/resizes/copies come in
from the hardware, dispatch to all clients.

Signed-off-by: Brian Kress <kressb@moose.net>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6621 c046a42c-6fe2-441c-8c8c-71466251a162