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
Ulf Lamping