Fix two wrong deps. I type them as gnome-shell-extensions-FOO.

Reported by: kwm


git-svn-id: svn://creme-brulee.marcuscom.com/ports/trunk@19779 df743ca5-7f9a-e211-a948-0013205c9059
Update gtk-doc to 1.21


git-svn-id: svn://creme-brulee.marcuscom.com/ports/trunk@19780 df743ca5-7f9a-e211-a948-0013205c9059