- renamed also the plasmaCrawlResults to have a consistent naming for url and image queues
- added a double-check for the images
- added additional queues for the images: all worse-quality images go there, so the queue can be used also if no sizes are given; no image is lost
- added a cleanup for the stacks so they cannot flood the memory
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@4722 6c8d7289-2bf4-0310-a012-ef5d649a1542