Ability to link all features to selected image

[jkeller2]

As an extension to the ability to link a CAP image to a feature add the ability to select a single CAP image and have that automatically linked to all dropped points/features until turned off. This would reduce the number of clicks in the workflow to link points to.

One idea would be once an image is selected hang a thumbnail somewhere in the UI so the user knows that all future points will be linked to that image until it is disabled.