Fix isEditable reader implementation.
Log errors on unknown reader descriptors.
Update data url generation.
Write tests for editable context.
Improve media type reader.
Add tests for media type contexts.
Fix extractor reader.
Simplify PramaterizedReader.
Make context-menu scroll to node before triggering context-menu.
Make isPage false on contenteditables.
Add overflow support.
Add predicate context tests.
Add test for extractor reader.
Add tests for overflows.
Fix rendering of nested items.
Update matching logic to avoid rendering empty groups.
Update code to cause DOM mutations only before context menu redraw.
Write tests for menus.