posixacl.rb provider check_recursive fix

2nd try at this pull request thing, thanks for the patience.

Fixed bug where getfacl/setfacl commands in posixacl.rb were being called with empty string arguments when acl param recursive was false. This triggered a syntax error in the command because of how execve passes args to programs.

* Part of this fix was making the setfacl/getfacl calls dumber using conditionals. There may be a more clever way to implement this but I just learned enough Ruby to make this work.

Fixed acl :recursive param in type/acl.rb to use :true and :false, and check_recursive in posixacl.rb to return boolean true or false