Add Page\n

Add another page to the current button style.

The left arrows add a page before the current page.
The new page takes the page number of the current page.
The current page and all subsequent pages are renumbered.

The right arrow adds a page after the current page.  The new page takes
a page number one greater than the current page, and subsequent pages are
renumbered.

\nDelete Page\n
This button deletes the current page.
