Grok

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- Make sure the correct layout is retrieved for layout aware form components
too.

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- Import the grokcore.layout.layout directive into the grok namespace too.

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- Update version requirements.

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- Split off the Application component and the local_utility directive to
grokcore.site. A backwards compatibility import for Application is left
in place.

- Split off the catalog and indexing components from grok into
grokcore.catalog.

- The permissions() directive, the Permission component and the Role
component moved from grok to grokcore.security. The grok package imports
these component, so they can still be accessed through the grok api.

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- Added imports for `querySubscriptions()`, `queryMultiSubscriptions()`,
`queryOrderedSubscriptions()` and `queryOrderedMultiSubscriptions()` functions
that complement the Subscriptions and MultiSubscriptions components.

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- Incorporate grokcore.chameleon and have it configured by default.

- Expose the Layout, Page, AddFormPage, EditFormPage, DisplayFormPage and
FormPage components that are brought by grokcore.layout. The grok variants
mixin application_url() and flash() functionality typically found in grok's
viewish components.

- Expose the ExecptionPage, NotFoundPage and UnauthorizedPage component from
grokcore.layout.

- Expose the ContentProvider component from grokcore.view

- Declare the name "index" as default view name for error views.