Add key_value::operator>
Add key_value::operator>

UIKit0/thrust,julianromera/thrust,lishi0927/thrust,allendaicool/thrust,h1arshad/thrust,google-code-export/thrust,lishi0927/thrust,levendlee/thrust,malenie/thrust,lishi0927/thrust,allendaicool/thrust,h1arshad/thrust,julianromera/thrust,lishi0927/thrust,Vishwa07/thrust,rdmenezes/thrust,bfurtaw/thrust,levendlee/thrust,Vishwa07/thrust,hemmingway/thrust,google-code-export/thrust,levendlee/thrust,rdmenezes/thrust,malenie/thrust,bfurtaw/thrust,hemmingway/thrust,hemmingway/thrust,h1arshad/thrust,allendaicool/thrust,malenie/thrust,UIKit0/thrust,levendlee/thrust,rdmenezes/thrust,bfurtaw/thrust,julianromera/thrust,UIKit0/thrust,hemmingway/thrust,google-code-export/thrust,Vishwa07/thrust,julianromera/thrust,allendaicool/thrust,malenie/thrust,UIKit0/thrust,bfurtaw/thrust,rdmenezes/thrust,h1arshad/thrust,google-code-export/thrust,Vishwa07/thrust