functions for converting between host and network byte order. These
names are the de facto standard names for this functionality because
of the original BSD TCP/IP implementation. But they cause problems for
uIP/Contiki: some platforms define these names themselves (Mac OS,
most notably), causing compilation problems for Contiki on those
platforms.
This commit changes all htons to uip_htons instead. Same goes for
htonl, ntohs, and ntohl. All-caps versions as well.
Now tcpip_output() is a function pointer that is supposed to be set via the macro tcpip_set_outputfunc(). Packet drivers do so on process startup.
Thus if there are several packet drivers in a Contiki system the one started last is the one actually used. This behaviour is especially useful for the 'IP forwarding' "meta" packet driver.
This change means that one needs to select _ONE_ cfs implementation at Contiki library link time. But this doesn't appear to be an issue as all platforms have their "favorite" implementation anyway.
