P: Add support to quickly Crop in Grid View

Add support for "Quick Crop" to quickly adjust a photo's crop from the Grid View in Library instead of having to switch to Develop, and then back.

Using LR since 1.0 professionally. Editing 1000s of wedding images, this would save a huge cumulative nickle-and-dime cost of editing. I can quickly changed exposure, white balance in Grid. Why can't I chnage crop in Grid view?