urls.py
 - clean up links

views.py
- remove unnecessary fields from TransactionCreate form, but make sure the
  fields that are needed are there.
- check to make sure the right owner is allowed in TransactionCreate.

HoldingView.html
- Various improvements in look and feel.
- Account for new stock being added and don't show other areas.

login.html
- use new bootstrap snippet to make it look nice.