Language bar: emphasise grouping a bit more

[jayfoad]

Following on from #191, I still think it would be nice if the grouping of glyphs on the language bar was emphasised a bit more:

1. You should never get a line break in the middle of a group.
2. Perhaps put a box around each group, or something like that, to make them more visually distinct?

[mkromberg]

I also feel quite strongly that visually enhancing the groups makes the language bar easier to use.

[abrudz]

I also think we should delimit the groups better. But there is really no reason to separate them more if they are not sensible, so I think we should make a few large, but meaningful groups and lock them down, similar to what TryAPL has. (I don't find the ability to change the order useful at all.) If we have really good groupings, we can even label them (like TryAPL does).

Maybe something like this:

Notice also how the four groups have subtle sub-groups, similar to the existing spacing.

Each group should wrap separately when the window is narrowed, and the subgroups should never be broken:

Of course, the above mock-ups should not be taken as a suggestion on how the groupings and subgroupings should be, but just as a visual example of how it could look.