monitor: Rework terminal management (Jan Kiszka)

Remove the static MAX_MON limit by managing monitor terminals in a
linked list.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6712 c046a42c-6fe2-441c-8c8c-71466251a162
