add ability to split thumbnails on several pages, suggested by Till
[booh] / lib / booh /
drwxr-xr-x   ..
-rw-r--r-- 11392 GtkAutoTable.rb
-rw-r--r-- 2259 UndoHandler.rb
-rw-r--r-- 19163 booh-lib.rb
-rw-r--r-- 15118 html-merges.rb
-rw-r--r-- 611 pre-setup.rb