Closes #86 - fix documentation about TranslationManager's get_queryset, untranslated and language methods
Fix #142: allow access to translated attributes during model save.

Change the way that TranslatableModelForm.save() constructs the instance, to
ensure that translations are created and populated before we try to save the
master instance.
Use assertEqual in tests instead of assertTrue.

Makes test failure messages more useful. No practical change except that
one wrong assertion is fixed:

	self.assertTrue(response.status_code, 200)
Closes #139 - detect access to translated field on untranslated instance and:
-> raise an AttributeError, which is the correct semantic for a descriptor
-> provide a more helpful exception message
-> retain compatibility with code that may already catch a DoesNotExist exception. We should deprecate that though
Closes #130 - use translation accessor instead of direct query to access translations
Merge pull request #166 from spectras/lazy_prefetch_130

Closes #130 - use translation accessor instead of direct query to access translations
Merge pull request #139 from spectras/notranslation_warn_139

Detect access to translated field on untranslated instance and raise an AttributeError
Initial Django 1.7 compatibility fixes. Fixes deprecation warnings as well.
Updated Django versions for travis build. Added Django branch 1.7.x.