Fixed minor merge issues between pulls #1, #2 and #3 and previous unstaged commits.
* High-score files now stay at `~/.nsnake/high-scores.bin`.
  This way, each user has it's own and we avoid having to read/write from/to `/var/games`

* High-score dirs are created at runtime.
  So we don't create the directory via Makefile - every time the user
  runs nsnake it assures the high-score directory and file exists.