Ensure runserver_plus serves staticfiles

From Django 1.3, staticfiles app had been merged into django codebase.
But, one can still install staticfiles app from its own repository to
make use of new features. In this case runserver_plus should serve
static files correctly.
Merge pull request #321 from tayfun/runserver_plus_external_staticfiles

Ensure runserver_plus serves staticfiles
Replace assertEquals with assertEqual
Merge pull request #325 from Vladimiroff/py3k_compatible_tests

Replace assertEquals with assertEqual
reset_db made to work with spatialite (backend from geodjango)
Merge pull request #326 from skyjur/master

reset_db does not work with spatialite
small addition to pull request 326, print correct engine name for spatialite
Need dir=both for graphviz arrow heads.
Merge pull request #328 from BangorUniversity/master

Fix graphviz arrow heads
merge with new dumpscript
merge and added option atomic transactions
Merge pull request #301 from marcosdiez/master

 dumpscript: more 3 hooks to import_helper.py and we now use a class for that
fix py33 except statement, added transaction.commit_on_success hint
fix sqldiff forgetting to report parameters of field types when column type has changed, highlighted by issue #330
resulting database column types should be lowercased for comparison after stripping parameters, see issue #330
replaced u"" with six.u("") in several places for #308
removed fallback uuid module (related to #308)
add uuid importerror catch
Add assertions that highlight issue #329
Fix #329

Removing contribute_to_class doesn't break any existing test and solves
the issue with multi-table inheritance described at #329 and highlighted
by the assertions added in 25b1e260769e418d0e4033e864a726e249dddbe2

contribute_to_class had been added as a workaround for Django
bug https://code.djangoproject.com/ticket/13696 Unfortunately this was
not the right thing to do as it has unwanted side-effects. An auto
field is an implicit primary added automatically by Django.
UUIDField is not an auto field.  The inline editing bug has to be
fixed in Django. django_extensions' UUIDField was doing the right
thing when it wasn't pretending to be an auto field.