WriterFullScreenView/pt

The goal is to propose to the user of module Writer a special mode dedicated to writing without any distraction.

Specification
OpenOffice already provide a "FullScreen" mode in Writer. The idea is to enhanced and improve it for children.

The fullscreen mode for OOo4kids should offer the following characteristics:
 * FullScreen.
 * Write in white with background black. Or the opposite. (Could be a preference)
 * Zoom to be "adapted to width" automatically
 * Keep some shortcuts to page up/down, start/end of documents, …
 * Remove the rulers
 * Remove the grid


 * FullScreen view in iWork
 * FullScreen view in Bean (see at middle of the page)
 * FullScreen in Mellel (see item #6)
 * WriterRoom (a full-screen writing environment).