Bundle a collection

 * For example,
   https://en.wikibooks.org/wiki/Wikibooks:Collections/Blender_3D:_Noob_to_Pro

   would be called as,
   ./bin/mw-ocg-bundler -p enwikibooks
                        -c Wikibooks:Collections/Blender_3D:_Noob_to_Pro

 * Simulates the Collection extension, bookcmd=render_collection

Change-Id: Ia855b35d9c69e673426bc83f8dce69f06216c7d9
Merge "Bundle a collection"