[authors] Calc Guide Ch5 (Graphics) revised

[Jean Hollis Weber]

While going through Emma's review comments on CG Ch5, I decided to 
make some other changes to the chapter. I have now added some new 
material, amended at least one graphic, and rewritten other sections 
to be more like the info in the Writer Guide.

I have submitted the chapter for another review.
http://www.oooauthors.org/english/userguide3/calc3/cg3_draft/0305CG3-UsingGraphicsInCalc_JHW_20091124.odt/view

--Jean