Patches for Yosemite

This gets rippled going on Yosemite.

After upgrading you have to re-install command-line tools prior to building:
$ xcode-select --install

Tested on both Mavericks and Yosemite.  Passes Travis.
@josh-ripple @niq
Probably put these inside an ifdef:

    #ifdef htonll
    #undef htonll
    #endif

Reason: undefining an undefined symbol generates warnings on gcc.