Initial commit for view-links-refactor branch.

The motivation behind these changes is the ability to add edit links
that are nested lists.  This allows us to add another dropdown to the
edit bar, from kotti.multilingual.

action_links has disappeared from type_info.  Needs b/w compatiblity.
Also, a usage example.
Minor changes to second tutorial (pep8 compliance,
mentioning template reloading)
Add multifile content upload.  This are actually cherrypicked commits from another branch to keep the git history clear.
Minor fix to second tutorial
Added third part of the tutorial, user interaction
Work around an issue with our event subscriber, which has problems cleaning things up.
Even though it is not PEP8 compliant, it should look like it
actually does. If it's fixed in the paster, we should also fix
it here.
Filter directly in the DB query, minor change to wording.
Filter directly in query.
Merge remote-tracking branch 'origin/master' into feature/contents_upload

# By Andreas Kaiser (4) and others
# Via Andreas Kaiser (1) and others
* origin/master:
  Require kotti_tinymce 0.4b2
  Don't require unreleased versions.
  Require deform_bootstrap 0.2.10.
  Update some requirements' versions.
  Update kotti_tinymce to version 4.0.2.
  Change because of changes in deform_bootstrap
  Change because of changes in deform_bootstrap
  Added css for error validation on tabbed forms.
Merge remote-tracking branch 'Kotti/master' into feature/contents_upload

* Kotti/master:
  Require kotti_tinymce 0.4b3.
Require kotti_tinymce 0.4b4.
Changed the wording to be more in line with the code
Fixed IndentationError and added a little more info
Modifies few translations
Merging latest changes.
Merge remote-tracking branch 'upstream/master' into review_tutorial_docs
Added my name to the CONTRIBUTORS.txt (forgot before)
Needs to use .prop instead of .attr. Also deleted the unused
function variable and changed .is to .checked as it is way
faster (http://jsperf.com/prop-vs-ischecked/5).
Merge pull request #258 from nightmarebadger/fix_select_all_checkbox

Fix select all checkbox in contents view
Fix #252: Wrap templates where extract_messages failed with <tal:block>