rewrite unit test for Context Projection

Fix mkDirRecursively

Change-Id: Ie09fd666ca208994f22e9f83af6072f4d5e6aa1a

remove usused arguments for maxout_layer, refine notes for pad_layer

Rename Python function DataBase into create_data_config_proto

This reverts commit ab279bee.

Using override keyword in Layer

One bug fix and two new features

fix paddle docker hub path (paddledev/paddle not paddle-dev/paddle)

Remove compile warning on AppleClang 8.0 in BufferArg.h

* CHECK_XX in glog need the left and right values are both signed or
  unsigned integer. So we could use integer literal syntax in C/C++
  to make literal unsigned or signed. Add suffix 'UL' means unsigned
  long.

route53 config with screenshots added

change the parameter position of gru_step_layer from 1 back to 0

* 'develop' of https://github.com/PaddlePaddle/Paddle:
  switch the parameter index in GruStepLayer in test_LayerGrad
  make gru_group parameters sharable