cache invalidation fix
adds language tabs on page creation
breadcrump working again
Merge pull request #2974 from digi604/fix-2946

adds language tabs on page creation
come out of force language on exception
Merge branch 'develop' of github.com:divio/django-cms into develop
Merge branch 'develop' into fix-2938
invalidate page cache on restart
updated docs
pyflakes fixes
add never cache headers for dynamic pages
cleanup
Merge pull request #2977 from digi604/fix-2938

Fix 2938 (cache invalidation on restart)
Merge pull request #2978 from FinalAngel/develop

Fixes filter and param issues within sideframe
fixes #2980
fixes imports
Use default instance namespace

Use default instance namespace for app_hooks when required but the user didn't supply an "application instance namespace"
Merge pull request #2984 from mkoistinen/use_default_instance_namespace

Address #2612 - Use default instance namespace
Update the plugin/app_hook/menu tutorial

Update the plugin/app_hook/menu tutorial from Django 1.2 (which is no longer supported by django-CMS) to Django 1.6's tutorial.
Merge pull request #2985 from mkoistinen/update_tutorial

Update the plugin/app_hook/menu tutorial