Fixed Mac OSX build warning except VRP part and boost 1.56 compatibility issue

The details are described at upstream https://github.com/pgRouting/pgrouting/issues/267 and https://github.com/pgRouting/pgrouting/issues/274.
I confirmed that whole unit tests work correctly on Mac OSX by executing tools/test-runner.pl with "-ignorenotice".
I also confirmed that MinGW(64bit) build is no problem.