page moderation migration and signal refactor
Merge branch 'digi604-link-remove' into feature/remove-plugins

Conflicts:
	cms/plugins/teaser/migrations/0002_publisher2.py
	cms/plugins/video/migrations/0002_color_mute_controller.py
	cms/plugins/video/migrations/0003_newplayer_step1.py
	cms/plugins/video/migrations/0004_newplayer_step2.py
	cms/plugins/video/migrations/0005_newplayer_step3.py
	cms/plugins/video/migrations/0006_newplayer_step4.py
	cms/plugins/video/migrations/0007_newplayer_step5.py
	cms/test_utils/cli.py
	cms/tests/plugins.py
	test_requirements/requirements_base.txt
Merge pull request #2575 from mkoistinen/issue_2432_fix

Fix for issue 2432
Merge pull request #2579 from ojii/nicer-deprecation-of-placeholder-tags

Nicer deprecation for placeholder_tags
Don't rename cms plugin tables when tables are not available
Added plugin rename check for m2m fields

-> ReverseManyRelatedObjectsDescriptor
More obvious failure if SITE_ID is non-int

* get_cms_settings now raises an ImproperlyConfigured exception if
  SITE_ID is not an integer (when 'LANGUAGES' is accessed).
* `cms check` now shows an error if SITE_ID is not an integer
added upgrade instructions
Merge pull request #2582 from Chive/feature/fix-table-rename

Don't rename cms plugin tables when tables are not available
signals working again
fix
fixed docs syntax error
fixed tests
changelog
Merge pull request #2584 from ojii/handle-non-int-site-ids-better

More obvious failure if SITE_ID is non-int
debug server signal
Merge pull request #2578 from digi604/post-populate

Post template render populate for toolbars
signals fixed, test fixed, testserver autoreloads apphoook... wooot
Merge pull request #2581 from Chive/feature/remove-plugins

Removing the plugins from the CMS Core and putting them into separate repos instead
don't print restart signal for tests