Add WQP services (issue #35)

[jbousquin]

1. Implemented the seven services outlined in issue WQP TODO: implement other services like Organization, Activity, etc. #35 via brute force (7 new functions in wqp.py) following structure of what_sites().
2. Updated base_url in wqp.wqp_url() to include data/, appears the existing services were being redirected to this base_url but new services did not. This should be more robust than adding 'data/' only to the new functions.
3. Added tests to wqp_test.py for each of the new functions following test_what_sites(), and updated request_url for pre-existing functions to == md.url.
4. Added appropriate text files for test results to data folder. The results for test_what_activities() are rather large, consider different query parameters.