update the styling of the Organize dialog

This is a maintenance/refinement task.

Please work with Jim and David M. (and get approval from Jen and Todd) to determine how the styling of the CTV (and possibly other parts?) in the Organize dialog needs to change to improve usability.

For instance, we may want to show a "dropped" style when someone has dragged a resource from one location and dropped it in a new location.

Also, we may not want to use the ExtJS default blue color on pick-up, etc.

Once decisions have been made and new stykes defined, please update the Style Guide accordingly and assign this task to David M. for implementation.