1. Support Inplace way for some functions.
2. Add new flexible constructor for XList.
3. Bug fixed.

Support reserved property in XTensor to indicate whether the data is reserved for backward.

Fix the minor bugs in IsSameShaped.

Fix the minor bugs in Transformer.

Find some fp16 bugs during decoding NMT system. We decide to roll back some codes to the last version. These codes need to be reviewed.

1. Update the installing methods in manual.
2. Remove the traditional installing way of Windows in manual.
3. Fix the bugs in CMake.

Find some bugs during training NMT system. We decide to roll back some codes to the last version. These codes need to be reviewed.