[c12990] Fix CMSG_DISMISS_CONTROLLED_VEHICLE

Close cmangos/issues#273

Signed-off-by: Yaki Khadafi <elsoldollo@gmail.com>

(based on commit f8a44c8)

Signed-off-by: Xfurry <xfurry@scriptdev2.com>
[c12991] Implemented vehicle opcodes that allow seat changing

Signed-off-by: Yaki Khadafi <elsoldollo@gmail.com>

(based on commit c2fb0fa)

Signed-off-by: Xfurry <xfurry@scriptdev2.com>