Add bazel installation to the Dockerfiles

Add SIMD flags for runtime check

Refine use_concepts.rst

Fix nvcc stray character Issue #760

add file extensions in doc/

Change "Baidu, Inc" into "PaddlePaddle Authors"

Accelerating image processing for CNN

Refine documentation of hierarchical-rnn.rst

Refine docker install doc and FAQ for gpu driver

Upgrade compiler‘s minimum version

Refine quick start index.rst chinese docs

- Put the 'ARG DEBIAN_FRONTEND=noninteractive' ahead of the first
  'apt-get install' invoke.
- Add comments to Dockerfiles to explain why we're adding Bazel
  installation.
Signed-off-by: NLi Peng <lipeng@unisound.com>

Also add DEBIAN_FRONTEND=noninteractive to suppress the debconf
messages.

refine dataprovider related rst

Update documents to init submodule.

Remove sparse length limits

Integrate warp-ctc as WarpCTCLayer, including unit test and layer interface.

Add unittest related #653