Add experimental support for U. F. O. groups and group kerns.

[frank-trampe]

This relates to #1367, #1634, and #1653.

[adrientetar]

🏁

[frank-trampe]

Hi, @adrientetar.

I don't mean to impose such a heavy task, but would you be willing to do the code review?

[adrientetar]

Sometimes in the weekend, yes.

[frank-trampe]

@monkeyiq, the Macintosh build on Travis is failing, and I cannot figure out why. Can you take a look?

[davelab6]

@monkeyiq please look into this :)

[adrientetar]

@frank-trampe Have you tested it with other editors? My Macintosh machine is broken just now. @davelab6 Can you test it?

[frank-trampe]

I'll be able to test it this week. (I got a Macintosh specifically for this purpose.)

[davelab6]

Where can I get a mac binary?

[adrientetar]

(I got a Macintosh specifically for this purpose.)

Do you mean you bought one? I need to get back to a clean install that works personally…

[frank-trampe]

@adrientetar, the idea is to run a few other typeface editors (most of which do not like Linux) in order to test data interchange.