Added the generation of document_id -> page_id maps.
In lsimodel, print_topics now prints topics, and log_topics logs them.
Fixed a bug in the generation of the page_id vector of wikicorpus.py
Added multiplication of title effect.
Adapted wikicorpus, so we can iterate on it while retrieving page_ids.
New treatment of titles.
checkpoint
Merge branch 'luca' into vb
Added utf-8 encoding explicitly for dictionary.
Added the option of splitting a wiki in sections to build the semantic models.