pre-populate choices where possible

[triceam]

When performing an action, prepopulate field selection where applicable. IE: bx cf push could show a quick pick list of all cf apps, and let you select which one you want to push.

[triceam]

Added support for array-based quick pick lists. Wouldn't be hard to add Thenable (promises) pick list data provider for async lookups. if we want to do this