Quill binding

[mweidner037]

CRichText binding for the Quill rich-text editor.

The rich-text demo is close but needs:

• Generalization / conversion to binding
• Support for embeds
• Quill line formatting inconsistency #251 fix

[mweidner037]

• Use in rich-text and recipe-editor demos, fileshare-recipe-editor, and fileshare-rich-text-demo