Log Message:
Update plone3 package to 3.1.7.

Change log

* Allow _ as a valid character in file names and URLs. Do not remove #
  from file names. It only has a special meaning for URLs.
* Enable unlock on unload for inline edits

Updated packages and products

    * Products.CMFPlone 3.1.7
    * plone.i18n 1.0.7
    * archetypes.kss 1.4.3