added a root_level argument to show_sub_menu
added some tests for root_level in show_sub_menu
a better docstring for root_level
updated docs
added a root_level argument to show_sub_menu
added some tests for root_level in show_sub_menu
a better docstring for root_level
updated docs
nephews argument for show_sub_menu
resolving merge conflict
speed up of menu fixtures for tests.  why go back to the db when create_page returns the page object.
changed api so root_level is the level you start at, not after
show_sub_menu 100 0 works now, also docs updated
CMS_PERMISSION: optionally use raw id user lookups

The "view restrictions" and "page permissions" inlines on the "page"
admin change forms can cause performance problems where there are many
thousands of users being put into simple select boxes. Added a new
setting (CMS_RAW_ID_USERS) that, if set, forces the inlines on that page
to use standard Django admin "raw ID" lookups rather than select boxes.
The restriction on which users may be selected should still be honoured
by the new widget because we set the 'limit_choices_to' attribute to be
the same as the queryset on the original widget.

Using raw_id_fields in combination with limit_choices_to blows up if you
have many thousands of users. For this reason, we only apply this limit
if the number of users is relatively small (< 500, though that figure is
somewhat arbitrary). If the number of users we need to limit to is
greater than that, we use the usual input field instead unless the user
is a CMS superuser, in which case we bypass the limit. Unfortunately,
this means that non-superusers won't see any benefit from this change.
Removed unused import
.count() rather than len() for performance boost
CMS_RAW_ID_USERS: added default setting + docs

Also removed the previous version bump so it can merge cleanly upstream.
clearer conditional check
Revert "removed two redundant icons; use Django's instead"

This reverts commit e353318fe7ccbb219391274ba8cdb774a3fbb275.
Merge branch 'develop'