Allow explicit specification of navigation extensions, deprecate the auto-discovery behavior
Workaround for a django bug that causes a "django.security.DisallowedModelAdminToField The field id cannot be referenced." when clicking on a raw_id_field referencing a MediaFile.

This should help for #552 until fixed django versions are released.
FeinCMS v1.10.1
Merge branch 'master' into next

* master:
  FeinCMS v1.10.1
  Workaround for a django bug that causes a "django.security.DisallowedModelAdminToField The field id cannot be referenced." when clicking on a raw_id_field referencing a MediaFile.

Conflicts:
	feincms/__init__.py
Follow the same schema as the page and translations cache when creating app_reverse cache keys
Move the app reverse cache key generation into an ApplicationContent class method, similar to closest_match
Be explicit about the app reverse cache timeout
One last missing method rename
Avoid importing django.contrib.sites.models if possible
Fallback import for get_current_site
Implement a composition of Inheritance 2.0 and response header setting

Refs #553.
Fix an inconsistency in feincms_nav (more details in the release notes)
Fix page_is_active with page pretenders
Add a test for page_is_active
Add @unpack tests
We do not have to support _meta.module_name anymore
@monkeypatch_class was never used inside FeinCMS, remove it
Remove another helper which is obsolete now that the minimum required Django version is 1.6
Update the release notes for 1.11
Merge remote-tracking branch 'origin/mk/explicit-navext' into next

* origin/mk/explicit-navext:
  Allow explicit specification of navigation extensions, deprecate the auto-discovery behavior