consistent loading of plugins by priority order

git-svn-id: http://svn.resourcespace.org/svn/resourcespace@5644 c08608d7-6e46-0410-86ca-f2a6f1370df5
add title to geographic search

git-svn-id: http://svn.resourcespace.org/svn/resourcespace@5645 c08608d7-6e46-0410-86ca-f2a6f1370df5
additional hook in preview area

git-svn-id: http://svn.resourcespace.org/svn/resourcespace@5646 c08608d7-6e46-0410-86ca-f2a6f1370df5
additional hook in preview area (when preview image is present)

git-svn-id: http://svn.resourcespace.org/svn/resourcespace@5647 c08608d7-6e46-0410-86ca-f2a6f1370df5