Reorganising the folders and adding TREC CS data

Reorganising the folders of the repository and adding data for TREC CS
2014.
Adding data

Adding Foursquare categories and example ids to data. Updating
.gitignore.
Updating jars

Updating composite-contextual-suggester.jar and
foursquare-venue-fetcher.jar.
Updating source code

Correcting a mistake related to the venue ids in VenueHandler.
Updating README

Updating README.