Writer Guide chapters for review

Now that the LO conference is over, and I'm back from my latest
travels, it's time to move along with GS 5.2 and WG 5.2.

Olivier, I've replaced the WG Preface file I uploaded to ODFAuthors a
month ago. When you (or anyone) have a chance, please review my work
on the Preface and Chapters 1 and 2. Did I leave out anything
important that's new? Did I forget to change anything?

I'll look at what you've done on GS. I'll also continue with updating WG Ch3.

--Jean