"klh10.h" includes "cenv.h".
This is possibly needed on systems that need some defines before
including system headers, for Long File Support.
I either moved an existing include line up or added #include "cenv.h"
where none of these was included before.
Note that most of the definitions in the "cenv.h" file are, or should be,
obsolete. Where still relevant, they should be detected by the
configure script.
The goal is to retire KLH10_NET_BPF, _PFLT, _DLPI and _LNX as much as possible.
However where ethernet addresses are manipulated, such operating system dependent methods still need to be used, since libpcap does not handle that.
Code for the other packet filters is still included but most likely does not work.
To use the new code, add -DKLH10_NET_PCAP to the Makefile(s).
