Changes with Aloha.Editor 1.4.45

Bugfix SUP-5481

In certain cases whitespace could not be deleted with the delete or backspace keys. This has been fixed.

Bugfix SUP-5832

When a row of a table was transformed into a header, and afterwards all rows were deleted,
the table itself was not deleted. This has been fixed now.
Also, after the selected rows/columns were deleted, the floating menu still showed table related tabs, which was
incorrect, because the table was not selected any more.