add bulidCell to the LSTM
add buildLSTM
finish lstm
Made some modification on Reccurent to make it work for LSTM and other table layers
delete some redundant code
make lstm work
add gradient check for lstm
add parameter methods to LSTM and add more tests to NarrowTable and SelectTable
make LSTM work correctly
add element-research rnn comparison test
fix reccurent forward bug and set timeDistributedCriterion sizeAverage to false, passed the test with Element-Research
add SplitTable
make lstm work
add more tests for lstm
Merge with recurrent
unchange sequential layer
add comments to lstm
remove unnecessary change
meet the code review
add parallel tag to LSTMPeepholeSpec
remove dropout arguments
make batch lstm pass tests
make LSTMPeephole pass the test
