ATT-6: TestHelper provides a replay method for saving a small image.
modified: api/src/test/java/org/openmrs/module/attachments/obs/TestHelper.java
new file: api/src/test/resources/attachments/OpenMRS_icon_100x100.png
Added skeletons of next unit tests + improved existing tests.
modified: api/src/test/java/org/openmrs/module/attachments/obs/ImageAttachmentHandlerIT.java