[Feature Request] Allow FileUpload toolbar customization similar to that of the Toolbar component.

[bdsexton]

I'm submitting a ...

[x] feature request => Please check if request is not on the roadmap already https://github.com/primefaces/primeng/wiki/Roadmap

Current behavior

The Toolbar component allows easy customization with custom input controls. The FileUpload component does not currently allow such customization for its toolbar.

Expected behavior

It would be nice if the FileUpload component could accommodate custom input controls, including different buttons, menus, and checkboxes.

Minimal reproduction of the problem with instructions

N/A - Just see the demos and documentation for the current states of the components.

• FileUpload
• Toolbar

What is the motivation / use case for changing the behavior?

It would be nice to be able to easily specify file-related information such as category in the FileUpload toolbar.

Please tell us about your environment:

• Angular version: ~2.1.1
• PrimeNG version: ~1.1.2
• Browser: all
• Language: all