Scalar Type Hints

Upgraded Memio to v2.0@alpha, meaning:

• PHP 5 support was dropped
• scalar arguments now get type hinted
• maximum method argument line length changed from 120 to 80
• opening curly brace changed to be on the same line as the method
  closing parenthesis, when arguments are on many lines
• properties changed to not have empty lines between them,
  except if they have PHPdoc