Thanks to ashikase for pointing out the needed linker and compiler flags.
Thanks to GiZMo for testing on his mac 10.5.4.
This also cleans up configure.in a little by adding appendMod.
git-svn-id: https://znc.svn.sourceforge.net/svnroot/znc/trunk@1258 726aef4b-f618-498e-8847-2d620e286838