ExtendedSelectAll() was originally invented to e.g. select the whole
document, change the language of the selection and then inmediately
(before the layout is updated) undo the selection.

When using it for "select all and doc starts with a table" purposes,
then footnotes shouldn't be selected, just like those are not selected
either, when the doc starts with a normal paragraph. Their anchor is
still selected, and that's enough to have correct delete and copy&paste.

Change-Id: I4fc49db628054a4b8a46effc2d0328eaabcaa9f8