Entropic Package.toml support

[Lars Willighagen]

(maybe not put everything in the same plugin, or just extract YAML/TOML packages on which other plugins can depend, and then move CFF because it is stand-alone)

Input

• @else/toml (possible conflict with Bib.TXT, of all things (which also opens up a bunch of opportunities)
• @entropic/package
• @entropic/url extends @else/url (if possible)

Output

• entropic (TOML/YAML(?)/Object)
• plain TOML? (but then also plain YAML)