Implemented automatic tests for inspectdb and tests on the reimported model.

This test can be run only manualy by tests/inspectdb/test.sh
Only for Django >= 1.5, because our inspectdb can not prevent related_name
clashes at Django 1.4 and requires manual editing.
Fixed test for inspectdb (slow_test) for Django 1.7. and improved.
Fixed error with "manage.py test --verbosity=2" in Django 1.7+

Django 1.7+ uses migrations internally if the verbosity is high.
Migrations in tests can not be disabled by old settings for South.

Conflicts:

	salesforce/testrunner/example/models.py
Fix a test for multiple databases for different sf_alias.
Fixed deprecation warning: renamed get_query_set to get_queryset.
Fixed whitespace/tabs
Comments on DatabaseFeatures, related settings.
Tests for old known unfixed bugs (skipped with a message)
Merge pull request #64 from hynekcer/bugfixes

Bugfixes