ImageMajick Support 1

test version of background shelling out to do image resizing
image to watermark over 300x250 images prohibiting copying
- Encounter.refreshAssetFormats() - a hint of the future?
- ImageProcessor.class - imagemagick (or whatever) background image resizing
- Shepherd.isAcceptableImageFile now static, so can be used more readily
- SinglePhotoVideo.scaleTo() and .scaleToWatermark()
- EncounterForm (new encounter) now calls refreshAssetFormats()
- encounterImagesEmbed.jsp now uses SinglePhotoVideo.scaleTo() if it can (and watermark variant)
- as does resetThumbnail.jsp
- updateAllImages.jsp - (poweruser only!) utility to create a shell script to update allllll derived images