seperate sim hinge rand loss layer with dot similayity layer, rename
sim_hinge_rank_loss_layer as hinge_rank_loss_layer, add test unit for
hinge_rank_loss_layer
	modified:   include/caffe/loss_layers.hpp
	modified:   src/caffe/layer_factory.cpp
	new file:   src/caffe/layers/hinge_rank_loss_layer.cpp
	deleted:    src/caffe/layers/sim_hinge_rank_loss_layer.cpp
	modified:   src/caffe/proto/caffe.proto
	new file:   src/caffe/test/test_hinge_rank_loss_layer.cpp