Add option to skip processing additional pages in multi-page TIFFs
Multipage TIFF files are processed as multipage documents with previews for each image in the file. Some software packages (possibly Silverfast) appear to create TIFFs that have the image duplicated across several "pages". We should add an app.conf option to skip multipage processing for TIFFs across the board in these cases. The default should remain to process all data.