Add a merge strategy from Google's work
Add dropout with Asynchronous RBM.
Epoch 30 without dropout.
Structure change from [100,100] to [500,5000,2000]
Change w1=1/thread_num.
Merge tag 'v0.10' into DropoutARBM

Run 20*10 experiments, result stable, accuracy less than v0.09.
Change w1 to 1/sqrt(thread_num).
Run experiments for ASGD approach to compare with ARBM.
Try to compare between different n_push and n_fetch settings.