Improved tokenize_pipes and cleaned up the code.
Merge branch 'master' of github.com:ilyanep/pintos-awesome

* 'master' of github.com:ilyanep/pintos-awesome:
  update DESIGNDOC
  Makefile changes
  Everything should work now
  Fixed special commands again
  two commands piped together works, three does not
  Trying to get pipes to work...

Conflicts:
	src/shell/mysh.c