Added support for decomposing components when drawing onto a Path using FontTools pen interface. A glyphSet option (None by default) is added to Path.getPen method, and to PathPen constructor.
This should be a mapping of drawable glyphs keyed by glyph name.
No longer silently ignore components, but raise an error if the glyphSet parameter (needed to resolve component references) is not provided when getting or constructing the PathPen (29, 32).