* The $TRAVIS_COMMIT_RANGE could be not existed, because the git history
  can be changed and rebased. Here we alway run Travis-CI when `git diff`
  cannot return the modified files.
* Also do not push docs update if is not PaddlePaddle/Paddle.

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

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

* But not reproduce the problem.

some tiny fix