add getitem function to FeatureSet class
add getitem function to FeatureSet class

gskielian/SimpleCV,hurdlea/SimpleCV,jlegendary/SimpleCV,beni55/SimpleCV,hayd/SimpleCV,jayrambhia/SimpleCV2,nils-werner/SimpleCV,jyt109/SimpleCV,onaclovtech/SimpleCV,onaclovtech/SimpleCV,beni55/SimpleCV,jayrambhia/SimpleCV2,jyt109/SimpleCV,nikhilgk/SimpleCV,gskielian/SimpleCV,sightmachine/SimpleCV2,hurdlea/SimpleCV,jlegendary/SimpleCV,nils-werner/SimpleCV,hayd/SimpleCV,nikhilgk/SimpleCV,beni55/SimpleCV,jyt109/SimpleCV,gskielian/SimpleCV,nikhilgk/SimpleCV,jyt109/SimpleCV,gskielian/SimpleCV,nils-werner/SimpleCV,sightmachine/SimpleCV,beni55/SimpleCV,sightmachine/SimpleCV,hayd/SimpleCV,gskielian/SimpleCV,tpltnt/SimpleCV,jayrambhia/SimpleCV2,tpltnt/SimpleCV,onaclovtech/SimpleCV,jyt109/SimpleCV,tpltnt/SimpleCV,jlegendary/SimpleCV,sightmachine/SimpleCV2,jayrambhia/SimpleCV2,jlegendary/SimpleCV,onaclovtech/SimpleCV,hurdlea/SimpleCV,nils-werner/SimpleCV,sightmachine/SimpleCV2,sightmachine/SimpleCV2,nils-werner/SimpleCV,hayd/SimpleCV,jlegendary/SimpleCV,sightmachine/SimpleCV,nikhilgk/SimpleCV,beni55/SimpleCV,hurdlea/SimpleCV,hayd/SimpleCV,hurdlea/SimpleCV,sightmachine/SimpleCV,tpltnt/SimpleCV,onaclovtech/SimpleCV,tpltnt/SimpleCV,sightmachine/SimpleCV,nikhilgk/SimpleCV