[x3d-public] draft X3D 4.1 prose for font files and libraries

[Michalis Kamburelis]

Rereading Don't answer to my question 4 (FontLibrary and EXTERNPROTO):
https://github.com/michaliskambi/x3d-tests/tree/master/font_library_questions/question_4

I see now that Don actually wants to allow FontLibrary in prototype
top-level. I guess this will be consistent with "4.3.2 Root nodes"
allowing FontLibrary too. OK, so this is more complication... now we
need to search proto instance(s) around given node first.

Regards,
Michalis