MacOS support changes, from Michael Tuexen (with some modifications):

MacOS support changes, from Michael Tuexen (with some modifications):

	replace "--with-plugindir" with "--with-plugins", and have the
	plugin directory optional - this allows plugins to be disabled;

	add "--traditional-cpp" on MacOS X/Darwin (Apple's "cc" compiler
	requires it, for some annoying reason, even though it is, as far
	as I know, GCC-based, and other GCC's don't require it);

	on MacOS X, don't use "pcap_version[]", as, for some annoying
	reason, libpcap on MacOS X doesn't define it.

Clean up some whitespace in the help messages for the configure script.

Move the AM_CONDITIONAL for SETUID_INSTALL after the point at which
"enable_setuid_install" is set, as it tests "enable_setuid_install".

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@3788 f5534014-38df-0310-8fa8-9805f1628bb7