cvfind crashes if all images in a project do not have the same size

[Bob-O-Rama]

Currently cvfind assumes all images in a project have uniform height and width. This various crashes throughout when images are not the same dimensions as the reference image. The "bug" aspect of this issue is cvfind crashing rather than reporting it is unable to support multiple sized tiles in the same project. cvfind should detect, report, and exit cleanly when it cannot handle the input project. See also Issue #7