using dumpcap as the capture child for Ethereal.
dumpcap is a plain console application now, even for Win32 (so no WinMain, create_console and special piping stuff reguired). The undocumented command line option -Z will switch dumpcap into "child mode", using binary instead of plain text output messages to communicate with a parent Ethereal.
Ethereal's main.c no longer needs to distinguish between child mode or not, so some simplifying here.
capture_sync.c has to call dumpcap in a "hidden window" mode using CreateProcess instead of spawnvp, otherwise an uggly console window would appear. The handles created by _pipe doesn't seem to be inheritable for this function, using CreatePipe instead.
The file capture_loop.c is only needed by dumpcap, removed from Ethereal link objects.
Some debugging aid added and other minor cleanup done.
svn path=/trunk/; revision=17256
remove a lot of redundant code from tethereal and use (move) stuff from capture_loop.c instead.
concentrate common capture related code in capture_opts.c, e.g. trying to find the right interface to capture from (command line option, preference, first usable) instead of duplicating this code over several files.
remove redundant code from dumpcap.c
this also implements command line option -D (and indexed interfaces at -i) for Ethereal and Dumpcap (as we have it in Tethereal already for a while)
svn path=/trunk/; revision=16787