DST should work with TransactionMiddleware

[Almad]

When exception occurs in tests and transactino middleware is enabled, panda is sad:

======================================================================
ERROR: tests.test_particular_formsxxx

---

Traceback (most recent call last):
File "/usr/lib64/python2.6/site-packages/nose/case.py", line 187, in runTest
self.test(_self.arg)
File "/home/lukas.linhart/projects/isis-all/jiskreni/tests/test_particular_forms.py", line 77, in test_zodiac_rendered
HTTP_X_REQUESTED_WITH='XMLHttpRequest'
File "/home/lukas.linhart/projects/isis-all/lib/python2.6/site-packages/django/test/client.py", line 330, in post
response = self.request(__r)
File "/home/lukas.linhart/projects/isis-all/lib/python2.6/site-packages/django/core/handlers/base.py", line 100, in get_response
response = callback(request, *callback_args, *_callback_kwargs)
File "/home/lukas.linhart/projects/isis-all/lib/python2.6/site-packages/django/utils/decorators.py", line 76, in _wrapped_view
response = view_func(request, _args, *_kwargs)
File "/home/lukas.linhart/projects/isis-all/isis/isis/accounts/views.py", line 131, in profile_form
'data' : form.as_data_json(profile=profile)
File "/home/lukas.linhart/projects/isis-all/isis/isis/accounts/forms.py", line 185, in as_data_json
data[name] = self.transform_value(field, data[name])
File "/home/lukas.linhart/projects/isis-all/isis/isis/accounts/forms.py", line 170, in transform_value
return self.field_renderers[field.class](field, value)
File "/home/lukas.linhart/projects/isis-all/isis/isis/accounts/forms.py", line 146, in
forms.ChoiceField : lambda f, v: dict(f.choices)[smart_str(v)],
KeyError: '1'

======================================================================
ERROR: tests.test_particular_forms.xxx

---

Traceback (most recent call last):
File "/usr/lib64/python2.6/site-packages/nose/case.py", line 133, in run
self.runTest(result)
File "/usr/lib64/python2.6/site-packages/nose/case.py", line 151, in runTest
test(result)
File "/usr/lib/python2.6/unittest.py", line 300, in call
return self.run(_args, *_kwds)
File "/usr/lib/python2.6/unittest.py", line 297, in run
result.stopTest(self)
File "/usr/lib64/python2.6/site-packages/nose/proxy.py", line 169, in stopTest
self.plugins.stopTest(self.test)
File "/usr/lib64/python2.6/site-packages/nose/plugins/manager.py", line 94, in call
return self.call(_arg, *_kw)
File "/usr/lib64/python2.6/site-packages/nose/plugins/manager.py", line 162, in simple
result = meth(_arg, *_kw)
File "/home/lukas.linhart/projects/isis-all/lib/python2.6/site-packages/djangosanetesting/noseplugins.py", line 478, in stopTest
transaction.leave_transaction_management()
File "/home/lukas.linhart/projects/isis-all/lib/python2.6/site-packages/django/db/transaction.py", line 84, in leave_transaction_management
raise TransactionManagementError("This code isn't under transaction management")
TransactionManagementError: This code isn't under transaction management

---

Ran 12 tests in 29.339s

Either disable middleware (not goot, IMO, as we then could not test transactions), or handle rollback better, and/or do arrangements in plugin (we cannot have reliable non-destructive tests then...)