restore loadCache() fixing a deserialization issue with bufferedImage (perf pbl)

git-svn-id: http://svn.openstreetmap.org/applications/editors/josm/plugins@29732 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4
Add export raster image in GeoTiff format

git-svn-id: http://svn.openstreetmap.org/applications/editors/josm/plugins@29733 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4