Clicking an image should not create a new ROI

[ctrueden]

From Michael Schmid:

Selecting an image by clicking into it (while a selection tool is active in the toolbar) should not create a new Roi (maybe unless the user drags to extend the roi). Even worse, clicking on the white space below an image (if the window is larger than the image, such as for the 'Blobs' sample, see also ticket #1060) currently also creates a new Roi.

Migrated-From: http://trac.imagej.net/ticket/1813