valgrind, kcachegrind for os 10.6

In case any mac devs haven't noticed:

#use valgrind once 10.6 support is in the main branch
sudo port install valgrind-devel
sudo port install kcachegrind
sudo port install graphviz

The kcachegrind port seems a bit wonky -- I've had to run it with elevated privileges ('sudo kcachegrind ').

Life just got better. Still waiting for a VTune etc. port for OS X; multicore (esp. TBB) profiling is still too hard.