in MRT mode, now updates parameters after every train sentence pair
in MRT mode, now updates parameters after every train sentence pair

yang1fan2/nematus,Proyag/nematus,yang1fan2/nematus,cshanbo/nematus,shuoyangd/nematus,rsennrich/nematus,EdinburghNLP/nematus,yang1fan2/nematus,yang1fan2/nematus,EdinburghNLP/nematus,shuoyangd/nematus,shuoyangd/nematus,rsennrich/nematus,EdinburghNLP/nematus,yang1fan2/nematus,rsennrich/nematus,EdinburghNLP/nematus,yang1fan2/nematus,yang1fan2/nematus,Proyag/nematus,cshanbo/nematus,cshanbo/nematus,rsennrich/nematus,yang1fan2/nematus,EdinburghNLP/nematus,rsennrich/nematus,shuoyangd/nematus,EdinburghNLP/nematus,Proyag/nematus,rsennrich/nematus,shuoyangd/nematus,Proyag/nematus,Proyag/nematus,cshanbo/nematus,yang1fan2/nematus,yang1fan2/nematus,shuoyangd/nematus,Proyag/nematus,cshanbo/nematus,cshanbo/nematus