Add version and commit information in capi config.h and use unofficial glog for Android API < 21. (#6113)

* Automatically configure the version and commit information in capi.

* Use the unofficial glog repository for building for Android (API < 21).

Also, change the `labels` to `label` for api consistency

* Enable the case N != ldc in EigenBlasGemm.

* Use MemoryHandle instead of direct calling of posix_memalign to alloc temporary memory.

* Use Eigen's slice() instead of a temporary memory.

* Add if-else for different cases in EigenBlasGemm (for N ?= ldc).

* Fix Proformance problem of enforce

* Fix missing `;` in code

* Fix CI

* add gflags for C++ unittest

Fix #6087

* add back print_operators_doc

* fix style check

* fix style check

* fix compile on cudnn7

* update

* update

* make silent

* Adding log loss operator

* Removing comments

* batch norm support matrix input

* update gpu code

* format code

* Make 'scale_op' supporting int and int64

* refine .cu file

* Add Python wrap of conv2d_transpose and its unittest

* Follow comments

* Fix format

1. Remove checking for num_neg_samples.
2. Fix dims of Output(Cost) and Input(Bias).
3. Renamed num_sampled_classes to num_neg_samples.
4. Add TODO for add more distribution sampler.
5. Init grad_data of bias by zero.
6. Refine comments.
7. Register a kernel for type double.