light refactoring of mac-demo to make even MORE modern

from your read me, you sound like a "progressive" person.  hopefully you can "get on board" with my stylistic changes (most can't)...  because if so.. I will "get into it"... and we can make this the BEST HTTP solution out there.  merge this and I will continue.. relentlessly...  :-)  (PS... CocoaHTTPServer has got to GO, lol)