Change `lower()` methods of DB commands to return unicode instead of str.
Change `lower()` methods of DB commands to return unicode instead of str.

This avoids Django Debug Toolbar (which is the only thing these methods exist for) getting a UnicodeDecodeError when a query contains a non-ascii character.

potatolondon/djangae,kirberich/djangae,kirberich/djangae,potatolondon/djangae,grzes/djangae,grzes/djangae,kirberich/djangae,grzes/djangae