to restore successful build status. travis DOCS job on master failed due to permisstion issue: https://travis-ci.org/baidu/Paddle/jobs/159851334  @reyoung, please resolve the permission issue.

* Add documentation build to ci test
* Push master branch doc changes to gh-pages branch

* Add some comments for CTC layer and fix CTC evalutors, also add interface test

Merge Baidu Internal Changes.

Change-Id: I8e0a8ea6fc2760652d9c76440a539c90860062d3

* modify RecurrentGradientMachine to support hasSubSeq sequence inlinks with the same number of sentence but different number of tokens for each sentence

Change-Id: Ic71f00a4bb346b4fa93e650dfb4b1a0d8d2338b0

Change-Id: Id66da7b7f5bf9ec80cc19b347e4fb822a5a6f197

* by default, synchronize default_stream after resizeAndCopyFrom
* add sync in some places after resizeAndCopyFrom using other streams

Change cos_sim to use CosSimLayer layer when size=1 and rename convex_comb_layer to linear_comb_layer     

Change cos_sim to use CosSimLayer layer when size=1 and rename convex_comb_layer to linear_comb_layer

Also add an unittest for layers.py, currently for a few things. More need to be added later.

Update from the original

* fix CUDNN_VERSION for backward of CudnnBatchNormLayer

* fix cudnn version number for BatchNorm

Update from the original

Custom stack trace refines

Lazy install Paddle wheels

Fix a PyDataProvider2 bug when use calc_batch_size

* Need PyGuard when set args for calc_batch_size

Change-Id: I2a72eb0a296a8cf297e2a53029d2602d85f40296

Merge branch 'custom_stack_trace_refines' of https://github.com/reyoung/Paddle into custom_stack_trace_refines

* Make layer stack trace shows ThreadId, Forward or Backward.

Change-Id: Iba1477adb8c9115c3a67ff2959bb5c878ca706c7

* Replace DataProviderWrapperConverter with DataProviderConverter in all
demo prediction scripts.

* Minor refinement of swig_py_paddle.rst to keep consistency with the
English version.

Fix bug in NO_AVX when using lstm

* libpaddle_cuda add wrong -mavx to some cpp files.

* Make layer stack trace shows ThreadId, Forward or Backward.

Change-Id: Iba1477adb8c9115c3a67ff2959bb5c878ca706c7