Add feature: Entity dependent edit drop down options

[wgorder]

Add the ability to populate cell drop dowmn menus from the row.entity by providing a path
to an options array on the entity. This allows for options to differ on a row by row basis.

closes #2309

[wgorder]

paging @PaulL1

Does this looks like good, any recommended adjustments? I think this could be useful in many use cases.

[PaulL1]

Looks good. Thanks for the contribution, I have merged.

[chandanjena]

I have a simple requirement. I am using angular ui-grid to display records fetched from database. I have a drop down field named Status. This drop down values are A, B, C, D, E. I need to display all the values if the logged in user ($scope.profile = Admin) is Admin. But if the user is Supervisor ($scope.profile = Supervisor) then, only A,B and C should be visible in the drop-down.
How can I achieve this? I'm very new to Angular as you could have found by now.

here is my columnDefs for the drop-down.
{ name: 'Status', field: 'Status', displayName: 'Status', editableCellTemplate: 'ui-grid/dropdownEditor',
cellFilter: 'mapStatus', editDropdownValueLabel: 'status', editDropdownOptionsArray: [
{ id: 'A', status: 'A' },
{ id: 'B', status: 'B' },
{ id: 'C', status: 'C' },
{ id: 'D', status: 'D' },
{ id: 'E', status: 'E' }]
}

Thnaks in advance.