Replace maining Packet allocations with PacketGetFromAlloc().

Replace remaining uses of:

    Packet *p = SCMalloc(SIZE_OF_PACKET);
    memset(p, 0, SIZE_OF_PACKET);
    p->pkt = ((uint8_t *)p) + sizeof(*p);

with:

    Packet *p = PacketGetFromAlloc();

This has the same function, but also does all the PACKET_INITIALIZE()
functions, so it is more correct.

Updated Copyright dates on modified files.

Fixed indentation on return 0; in conditionals.