import the user model from settings
check if the user model is already registered

Fix usage of overwriting the UserProfileAdmin because it will be under mezzanine.accounts in INSTALLED_APPS.
check django version instead of ImportError

Closes https://github.com/stephenmcd/mezzanine/issues/893
Restore comment
Use space indent instead of tab
Merge
Merge
Added caisbalderas.com to sites in README.
Update link to bootstrap in README
Do not show the in_menus field in page admin if PAGE_MENU_TEMPLATES is empty
Fix admin password reset page. Closes #909.
Merge
Clean up PAGE_MENU_TEMPLATES check in page admin.
Added Laurent Prodon to AUTHORS
Fix failing account tests for foreignkey and date/datetime fields on user profile models.
replace calls to jQuery to grp.jQuery
don't include jquery-ui since it's already included by Grappelli
Upgrade jQuery nestedSortable plugin to its latest version.

The isOverAxis function has been removed in jQueryUI 1.10.
update urls to filebrowser which are now namespaced
update default tinymce_setup.js with the one from Grappelli