Remove Legacy Code

[mrwunderbar666]

• All routes that do not belong to api
• All templates
• Refactor some dgraph.py functions and tidy up
• All Form generating features in the DGraph abstraction
• Flask-Login dependency
  • Remove all references to Flask Login
  • Re-Implement the UserMixin AnonymousUser and AnonymousUserMixin classes
  • Should also have an is_authenticated property (would likely be convenient
• Flask-Markdown dependency
• dgraph_types.py has plenty of WTF generating stuff, needs to go (e.g. choices_tuples)
• Rename Exceptions (InventoryValidationError -> ValidationError, etc)