fix bug in which renaming photo causes os.remove even when it's an in-place rename on case-insensitive systems; incorporate expressionmatch for filename search; minor comment cleanup
add photo and search css for narrow screens; incorporate new expressionmatch kit; entry_with_history cursor moves to end; albums indicate total filesize; etc
Create searchhelpers.py which normalize incoming search parameters.
Add argument give_back_parameters so we can more effectively return the normalized parameters to the user to learn from their mistakes.
Create objects.WarningBag and stop using the warnings module with the unclear warning-catcher.
Fix handling of photos without extensions (still needs improvement).
Adopt use of pathclass.Path in more places and keep thumbnail paths relative so that the entire _etiquette dir can be moved and still work right away.
Probably some other things
