[josm_imageryadjust] restore plugin sources (see #josm8753)

git-svn-id: http://svn.openstreetmap.org/applications/editors/josm/plugins@29607 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4
[josm_imageryadjust] see #josm8753, #josm8710 - Restore plugin, update to JOSM 5960, fix warnings

git-svn-id: http://svn.openstreetmap.org/applications/editors/josm/plugins@29608 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4
[josm_imageryadjust] see #josm8710 - update to JOSM 5960, fix warnings

git-svn-id: http://svn.openstreetmap.org/applications/editors/josm/plugins@29609 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4