Case statuses need status classes for Open and Close operations and admins should be able to view and edit case statuses. Case end date should be cleared for any status that does not belong to the 'Closed' status class.

1. Site admins want access to view and manage case statuses. Also a few case level processes are based on detecting statuses which 'mean' case is 'closed' or case is 'opened'. We will provide menu access, and over-ride the 'option_value.grouping' column to use it to store a string for the status class. Status class options for now are 'Opened' and 'Closed'.

1.1 Add navigation menu link - Case Statuses - under Administer >> CiviCase
1.2 For this option_group selector, expose the 'grouping' column values - column header = 'Status Class'.
1.3. Upgrade should set status class = 'Opened' for status.name = 'Opened' and status_name = 'Urgent'. Status class = 'Closed' for status.name = 'Closed'
1.4 Grouping field should be included in Add / Edit Case Status (option value) form. Label s/b 'Status Class'. This field is frozen (read-only) for is_reserved case statuses option value records. Also make sure we have formRule which prevents duplicate 'value' values in this option_group (i.e. each case_status must have a unique option_value.value integer value.

2. The code in Modify CRM_Case_Form_Activity_ChangeCaseStatus::endPostProcess() needs to be modified to use the status classes ('Opened' and 'Closed' - rather than specific status ID's to decide whether to set or clear the case end_date. Current logic also has a 'flaw' - we should set end_date back to NULL when case status is changed to ANY status which does NOT belong to the 'Closed' status class. (Current logic only sets end_date to NULL when the specific status_id with name = 'Open' is detected. Since Phys Health has > 1 status which 'means' Open - this is faulty logic.)