Corrected annotation

[knutnergaard]

This adresses mypy errors raised after refactoring of annotations.py and annotation of normalizers.py.

The following errors presist, which will be collected in #775:

font.py:64: error: Signature of "_reprContents" incompatible with supertype "BaseObject"  [override]
font.py:64: note:      Superclass:
font.py:64: note:          @classmethod
font.py:64: note:          def _reprContents(cls) -> List[str]
font.py:64: note:      Subclass:
font.py:64: note:          def _reprContents(self) -> List[str]
font.py:2061: error: Signature of "isCompatible" incompatible with supertype "InterpolationMixin"  [override]
font.py:2061: note:      Superclass:
font.py:2061: note:          def isCompatible(self, other: Any, cls: Type[Any]) -> Tuple[bool, Any]
font.py:2061: note:      Subclass:
font.py:2061: note:          def isCompatible(self, other: BaseFont) -> Tuple[bool, str]
font.py:2138: error: "str" has no attribute "fatal"  [attr-defined]
font.py:2138: error: "str" has no attribute "warning"  [attr-defined]
font.py:2139: error: "str" has no attribute "fatal"  [attr-defined]
font.py:2141: error: "str" has no attribute "warning"  [attr-defined]

[benkiel]

Two things, one just a question.

[benkiel]

@knutnergaard I quickly took care of that docstring issues, merging