cmake: allow installing cmake files into ${CMAKE_MODULES_DIR}/mac (which defaults to lib/cmake/mac)
cmake: on Apple only, provide a default install name and rpath, and use them.
cmake: make sure our local CMake Modules path comes first.
python: start and stop must return a bool; just make it True
python: packet_to_pdu does not need to self-start
Merge pull request #2 from michaelld/mld_fixes

Mld fixes