Changes with Aloha.Editor 1.4.19

Bugfix SUP-3387

Sometimes, when editables with configured content rules contained blocks, the content rules
were also applied to the block contents.
This has been fixed now.

Bugfix SUP-3284

The automatic tab selection of the toolbar upon scope change failed to check whether
the tab to be selected contained any visible children. This could cause the toolbar to
appear empty (with none of the visible tabs selected).
This has been fixed now.