Enable tests modules to auto-import all test files in their directories.
Merge branch 'release-0.10' of github.com:learningequality/ka-lite into testing_testing

Conflicts:
	kalite/central/tests/__init__.py
	kalite/main/tests/__init__.py
	kalite/securesync/tests/__init__.py
Added a helper function for importing * from all modules in a directory.
Tweaks to auto-import function.
Tweak to docstring for import_all_from function.
Removed "exclude_special_modules" param from "import_all_from".
Merge branch 'testing_testing' into release-0.10
Merge branch 'release-0.10' of github.com:learningequality/ka-lite into release-0.10

Conflicts:
	kalite/main/tests/__init__.py