Fixed bug with TypedList example

Fixes TypedList example that was failing in /doc/library/typed_list.txt. Also added unit tests for the 2 TypedLists example to prevent this in the future.

Issue was raised on mailing list : https://groups.google.com/forum/#!topic/theano-users/orib7a6ew-A
Yes. Scan relies on this in the function format (defined in scan_module/scan_op.py line 221)