Unoccupied sync validity checks

Fix for crashers or hacks which make unoccupied vehicle invisible

#if !defined IsNaN
    #define IsNaN(%0) ((%0) != (%0))
#endif

const UNOCCUPIED_SYNC = 209;

IPacket:UNOCCUPIED_SYNC(playerid, BitStream:bs)
{
    new unoccupiedData[PR_UnoccupiedSync];
 
    BS_IgnoreBits(bs, 8); // ignore packetid (byte)
    BS_ReadUnoccupiedSync(bs, unoccupiedData);

    if (IsNaN(unoccupiedData[PR_roll][0]) ||
        IsNaN(unoccupiedData[PR_roll][1]) ||
        IsNaN(unoccupiedData[PR_roll][2]) ||
        IsNaN(unoccupiedData[PR_direction][0]) ||
        IsNaN(unoccupiedData[PR_direction][1]) ||
        IsNaN(unoccupiedData[PR_direction][2]) ||
        IsNaN(unoccupiedData[PR_position][0]) ||
        IsNaN(unoccupiedData[PR_position][1]) ||
        IsNaN(unoccupiedData[PR_position][2]) ||
        IsNaN(unoccupiedData[PR_angularVelocity][0]) ||
        IsNaN(unoccupiedData[PR_angularVelocity][1]) ||
        IsNaN(unoccupiedData[PR_angularVelocity][2]) ||
        IsNaN(unoccupiedData[PR_velocity][0]) ||
        IsNaN(unoccupiedData[PR_velocity][1]) ||
        IsNaN(unoccupiedData[PR_velocity][2]) ||
        floatabs(unoccupiedData[PR_position][0]) >= 20000.0 ||
        floatabs(unoccupiedData[PR_position][1]) >= 20000.0 ||
        floatabs(unoccupiedData[PR_position][2]) >= 20000.0 ||
        floatabs(unoccupiedData[PR_angularVelocity][0]) >= 1.0 ||
        floatabs(unoccupiedData[PR_angularVelocity][1]) >= 1.0 ||
        floatabs(unoccupiedData[PR_angularVelocity][2]) >= 1.0 ||
        floatabs(unoccupiedData[PR_velocity][0]) >= 100.0 ||
        floatabs(unoccupiedData[PR_velocity][1]) >= 100.0 ||
        floatabs(unoccupiedData[PR_velocity][2]) >= 100.0
    ) {
        return 0; // ignore bad packet
    }

    return 1;
}