Responsive Buttons

[kragit]

If using Button Box within something like SuperTable in it's 'static table' configuration, buttons can extend beyond their container and appear under/cover up other fields when in Live Preview mode.

Current behavior:

Possible fix:

The width button can get a little tricky, as it's not one that would lend itself well to being split up and thus will have a limit to how small it could shrink and still be useable. Maybe possible to have it be responsive up to a certain number of sections? (1, 2, 3 and 4 could shrink a bit from default and still be very useable).