Created Sales ext which includes some new orms:
- IncidentCustomer with extension to reference customer
- OpportunityCustomer with extension to reference customer
- ToDoCustomer with extension to reference customer
- ProjectCustomer with extension to reference customer
and Extend Account to include reference to Customer.

Modified CRM ext to extend customer to include account relation.

Modified customer orm to create CustomerGroup and CustomerGroupCustomer orms.
issue #19129 create sales ext, modify crm and project crm extensions, modify customer orm
* Add customer group and customer group item to the existing customer orm file.
* Create a "sales" extension orm file that does the following:
  - Extends CRM Account to include a reference to customer
  - Add customer document orms for Account, Contact, Incident, Opportunity, To-Do and Project (i.e. ContactCustomer, ToDoCustomer etc.)
  - Extend the orms above to include the toMany relationships for the corresponding customer document.
* Modify the CRM extension so it will additionally
  - Extend Customer to include Account property
  - Extend Customer to include ContactRelations, IncidentRelations, OpportunityRelations and ToDoRelations
Merge branch 'master' of github.com:xtuple/database into 19129
incident #19129 - extend Customer - add contactCustomer, incidentCustomer, opportunityCustomer, toDoCustomer, and projectCustomer columns to Customer orm in crm ext
Merge branch '19129'
Merge branch 'master' of github.com:jrogelstad/database