Originally flyouts had ‘blocks’ and rectangular hidden ’buttons’
underneath the blocks. When UI buttons were added to flyounts, there
was a terminology collision. This change renames the original
background ‘buttons’ to ‘mats’. As in placemats or door mats.
* Rename flyout to flyout_base
* flyout_base minus horizontal and vertical code
* Add flyout_vertical and flyout_horizontal
* review fixes + toolbox and workspace use
* Fix hat block case
* rebuild uncompressed
* Fix travis problem
* Fix build problem