fix tr1/memory compile issue on OS X 10.9 for makefiles

Of compiles fine for me now on mavericks using the makefiles. Maybe this should be put in a clause checking if we are on OSX 10.9 as that is the only version I have tried. Would appreciate more testing before merging, however I think it can sneak in as most people on OSX will be compiling via Xcode so this shouldn't be catastrophic if it broke on other peoples boxes and needed a revert/fix.

For explanation, see
https://github.com/openframeworks/openFrameworks/commit/4b669b86c635257af6a764772d0d46df37677244