Added 'training_set' collection data model
Implemented the function to parse a User-Agent into keywords and moved around some function prototypes from detection.c to ann.h
Now a ParsedUserAgent struct can be passed to ann::run() function
Added a function prototype for get_weights()
Added get_weights() implementation and added a function body for run() function as well. Some minor updates to function prototypes.
Uncommented dbh_get_conn() in dbh_test function to test if MongoDB connection is successful