Have pager return Nones if the server returns null.

This temporarily resolves an issue where the TheMovieDb server returns
nulls in searches when a movie has been deleted but not yet flushed out
of the cache. This prevents the error internally, but does not attempt
to re-order to remove the nulls, so is merely passing the issue onto the
application using this library.

Refs #29
(cherry picked from commit 0d91e6fc4184c17c5a9d39e1b2a264602a47747d)
Enable --debug flag in test application.
(cherry picked from commit abae25afb73f967421eb7797a868a9bdb187c18c)
Add handling for 'null' results in TheMovieDb searches.

This adds handling for a temporary issue on TheMovieDb where the API can
return 'null' results for a search when the movie has been deleted but
not yet flushed from the cache servers.

See http://www.themoviedb.org/talk/522e418d760ee3380c10d5a2
(cherry picked from commit 983bb0e4353d361f6c54f0de0c0db683b8d3be1d)