1. Backward bugs fixed.
2. Fix the minor errors.

1. Move the New/Initial/Del Tensor functions from XTensor.* to XElement.*
2. Move IsSameShaped functions from XTensor.* to core/shape/IsSameShaped.*
3. Move CheckData functions from XTensor.* to core/utilities/CheckData.*

2. fix the bug of onehotandindex
3. modify the data initilization of transformer
4. add the DumpFormat (need reimplement)

1. Merge with Huchi branch (replace all requireLink with enableGrad that allows gradient computation for a tensor);
2. Update the global memory size (This may make the memory size a little bit larger than the old version).

2. Add MemManager class to manage the memory;
3. Use the new version XList;
4. Add a new interface to create Tensor;
5. Apply MemManager to FNNLM.

1. fixed the bug in the Spread function.  2. add compare and OnehotAndIndex function 3. optimize the code

fix a bug in the softmax function. It executes backward comptuation incorrectly (in the condition of cpu computation and NOLOSS).
I found this bug by chance, then I spent one night confirming that something must be wrong and I spent one night finding the location of bug.
Finally, I fixed this bug in five minutes.

1. add gather function 2. add cross entropy forward computation and backward computation 3. code optimization 4. merge with xiaotong-working branch