Add Entity basemodel
Fixing mapper_args options dict for Entity
Setting up Branch and User to use Entity basemodel
Add TimestampMixin and RefEntityMixin
Use TimestampMixin in CurrentStockItem model
Use TimestampMixin in Entity model, new Entity.full_name property
Using Entity as a base model for Supplier
Update User model
Update Product model to new supplier table
Update Contact model to use new supermodel Entity
Minor adjustment to Branch.manager relationship
Rename CurrentStockItem --> CurrentStock
ProductUnit.<description/abbr> now are required fields, better repr() for other models
Better repr()
Product now uses TimestampMixin