Under-the-hood refactoring

[jmarkovic]

While introducing the last PR ( #29 ), I've noticed that some classes keep a reference to the Context. This may be an undesirable since it only might be useful for initialisation.

I propose that the part that initialises typefaces is moved to MagicViews class and that MagicFonts remains the point where typefaces live and keep their references without any Context reference.

I'm willing to do this work, but would need to discuss every change as this may be a major release (if we choose to remove deprecated methods). Would you like future PRs to go to development branch or a new branch just for this?