Bug 1054326: Initial attempt to submit Imagecompare test framework and test cases int...

...o the main branch
With the new screenshot method, I probably won't need the temp directory.  But, it is crucial for the reference images folder to hold a set of images to compare against the collected screenshots during the normal test run, Since in non-reference image collecting test runs, what it does is to compare the reference images against the images just taken.  If the reference image folder has to be empty, then perhaps each test run needs a job that just copies the reference images from somewhere?