String freeze: Simplify mass node editing actions

This patch changes the weird update actions on the mass node editing form.

1. It unifies the terminology: approve is now named publish
2. It adds “to/from front page” to the promote action
3. It removes “the selected posts” from each action to make it easier to read
4. It adds a “Remove stickiness” function
5. It reorders the functionality so that contrary actions (publish/unpublish) are next to each other

I also reordered the functions in the source code.

(Filing this as bug report because the text (especially approve) are really confusing at the moment)