Add intrinsic elements to non polymorphic components (grommet#2525)

Contributes: grommet#2325

Signed-off-by: Orestis Ioannou <oorestisime@gmail.com>

Merge branch 'master' of https://github.com/grommet/grommet

Fixed checkbox placed inside a button. (grommet#2382)

* Fixed checkbox placed inside a button.

* fixed typo

Updated to beta7. fixed pack script. (grommet#2358)

Changed Diagram to reduce dependence on Stack, add more `thickness` o…

…ptions, add `anchor`. (grommet#2086)

* Changed Diagram to reduce dependence on Stack. Fixes GitHub issue grommet#2036.

* Changed Diagram to allow more thickness variety. Fixes GitHub issue grommet#2037.

* Changed Diagram to add anchor to connections. Fixes GitHub issue grommet#2038.