move vendor js into head for better reusability
make xlwt real optional

you can install it by `pip install django-xadmin[Excel]`
not render in __repr__

causing recursion with template panel in DebugToolbar
add a way to disable queryset.select_related in ListAdminView

it's unacceptable slow when sql inner joins multiple tables
also, only select_related the displaying fields to boost performance
add fields attr support when calling modelform_factory
actually #14529 already fixed in django 1.2 at least
fix context naming conflict of bookmark permissions
Merge branch 'refs/heads/bookmark-conflict'

Conflicts:
	xadmin/templates/xadmin/base.html
	xadmin/templates/xadmin/blocks/model_list.nav_menu.bookmarks.html