s3storage raises a IOError, if the file is not found
Invalidate url-to-page cache when the ct_tracker updates the page.

Should fix issue #347
Merge commit '50d11840d4c1dbe235707746fbd464dd0c6d318e' into next
add comment to page pretender

update comment to page pretender
make datepublisher save aware datetimes
do not crash if site module is not installed
Merge remote-tracking branch 'schmidsi/master'

* schmidsi/master:
  s3storage raises a IOError, if the file is not found
Fix get_navigation_url now that redirect_to has an overloaded meaning
Improve translation cloning UX and reduce magic.
Add id to checkbox
Merge branch 'master' into next

* master:
  s3storage raises a IOError, if the file is not found
Fixed Issue #351
Remove 'frontend_editing' cookie on Stop editing

FIX #351
As mentioned in
https://github.com/feincms/feincms/pull/350#issuecomment-8645705
PEP8 cleanup
Update frontendediting_request_processor docs
Add tests for frontend editing.

Also fix invalid invalid client test for frontend editing that
worked only because fe_box is never in 404 page.
Merge branch 'master' into next

* master:
  Add tests for frontend editing.
  Update frontendediting_request_processor docs
  PEP8 cleanup
  Remove 'frontend_editing' cookie on Stop editing

Conflicts:
	feincms/module/page/processors.py
Merge remote-tracking branch 'DrMeers/explicit_translation_cloning' into next

* DrMeers/explicit_translation_cloning:
  Add id to checkbox
  Improve translation cloning UX and reduce magic.
  One translation per language per item seems to make sense?
Merge remote-tracking branch 'sbaechler/master' into next

* sbaechler/master:
  do not crash if site module is not installed
  make datepublisher save aware datetimes
  add comment to page pretender
fix typos: i.e. stands for d.h. e.g. for z.B.