- Removes 'span' from being a valid part of alignment formats so it's
not used to align contents, since it's going to mostly be an inline
format, wheras you'd really want alignment on the parent block.
- Adds direction cleaning to all direction change events, to remove
direction styles and child direction controls which may complicate
matters and cause direction changes not to show.
- Makes text direction controls work with table cell range selections,
which TinyMCE does not consider by default, via manual handling.
For #4843
c290d01adb