GTK-Doc homepage updated

[Martyn Russell <martyn imendio com>]

Hi,

While updating the devhelp link for the gtk-doc pages, we noticed that
they were still old school and not up to date with the new style on gtk.org.

I have taken some time this morning to update those pages and to create
links between the the GTK+ pages and the GTK-Doc pages.

Stefan, I also updated the download page and the news page to include
the 1.10 release you did recently.

If anyone has any comments, let me know.

-- 
Regards,
Martyn