turn two functions into virtual ones and add a method to get the traindata
add two methods to get and set the traindata for ranker
modify variable names rl -> fvv(feature vector vector)
modify variable names rl -> fvv(feature vector vector)
add the intrusive_ptr.h to replace the base.h
add the intrusive_ptr.h to replace the base.h
add the intrusive_ptr.h to replace the base.h
add the intrusive_ptr.h to replace the base.h
turn the ranker variable into a pointer to implement inheritance for svmranker