Fix the plugins list: stop automagically building zbar, cog and rsvg split plugins...

Fix the plugins list: stop automagically building zbar, cog and rsvg split plugins as part of the non-split package due to them being forgotten to be added here before (add them now), cog/zbar is not packaged in-tree so not a big problem, but rsvg is; it will be a separate split package. Add missing Windows/OSX sys plugins to the list to avoid useless header/linkage checks that waste configure time for all -bad splits too - directsound, directdraw, osx_video, wininet, acm. Order the list per ./configure --help output. Add comments to old plugins that are not shipped by -bad anymore, for when they were removed, to remove them from the list once safe. Have not tracked down opengl and x removal yet though.