Web:Features: Restructure page outline

This doesn't modify the content, although I have a clear idea about it.
So some contents don't seem to fit to the headings.
Web: Extend and rewrite Features->Text input
Web: Rewrite and Extend Features->Usability
Web: Rewrite and Ext. Features->Extensible design
Web: Rewrite and Extend Features->Environment
Web:Features: Review of details
Web:Features: Move images with text

Move the images after text has moved too.

I'm not sure if we need new image(s) for Text input
and "Extensible design".
Web:Features: replace color2 by generic divClass
Web:Features: Change @ref to Community

Don't link to "pages" because that's incompatible with
PDF or info output.