Very bad fix for compiling on OSX.
* After switching to LLVM 3.4 I encounter linker errors on OSX for symbols
  from libcurses.
* My fix is to be sure -lcurses is included in the linking command.
* However, this "fix" might break every other platform. Perhaps the right way
  to do things is with autoconf, but I personally have no idea how that all
  works.