Add a comment about making an A4 book.
Add a comment about making an A4 book.

Patch by: Guido Ostkamp <subversion@ostkamp.fastmail.fm>

* doc/book/Makefile: Add commented out line for printing to A4 paper.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@850688 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion