Fixed template path.
Moved intra-field validation to models.
Set explicit field ordering.
Implemented generic page display.
Rather extend the base template.
Use a more meaningful id.
Moved URL to the abstract page model definition.

The redirecting functionality will be shared by pages.
Reworded title and help text.
Removed `display_on_register` field.

Legal pages imply this functionality.
Fixed URL generation.
`get_absolute_url` can be shared across page types.
Ignore current page when checking for existing virtual paths.
Implemented even more generic static page views.

Create/Update views will be built according to the type of page set in the
url pattern.
Use more sensible names for templates.
Reworded a bunch of strings.
Form action URL is not strictly necessary.
Refactored templates, further rewording.
Link admin page from breadcrumbs depending on the context.
Added static page model.

Fixes bug 2866.
Added convenience `locale_reverse_align` template tag.