String Version of Login Form

Adds the functionality to use just a string for the login form (vs individual word blanks), including all relevant tests, a function in the form to sanitize string input from form.cleaned_data, updates to the template, validation errors, etc. Words were removed from template; will need to backtrack in the next push to remove all relevant tests/formlogic/view logic relating to those parts of the form as this will be a major change.