Store login as non-lcased form.
Merge branch 'KA_test_lite' into case_free_usernames
Merge branch 'KA_test_lite' into case_free_usernames
self code-review: removing cruft, adding more comments, cleaning questionable structure
Merge remote-tracking branch 'origin/case_free_usernames' into case_free_usernames

Conflicts:
	kalite/central/tests/browser_tests.py
	kalite/main/tests/browser_tests.py
	kalite/utils/testing.py