pages: display a warning instead or raising exception if write fails: request.write sometimes raise an AttributeError. This case happens most of time when browser tab is closed or reloaded before the page has been written. fix 214

The work in this directory is licenced under a MPL/GPL/LGPL tri-license:
    - MPL 1.1
    - GPL 2 or later
    - LGPL 2 or later

Originally distributed by the Mozilla Foundation
Source: http://www.feedicons.com