* add nn.interpolate, test=develop

* fix interpolate typo, test=develop

* formate code, test=develop

* fix unitest, test=develop

* add test layers, test=develop

* add test layers, test=develop

* extract common function, test=develop

* reduce the threads for cuda10, test=develop

* update unitest, test=develop

* polish unitest, test=develop

* add dygraph test, test=develop

* format description, test=develop

* add 5D input check, test=develop

* fix doc, test=develop

* add approximation for gelu, test=develop

* add functional conv

* add test and doc for function convs, test=develop

* update ConvTransposeOp's InferShape and error message, test=develop

* add hsigmoid, row_conv in paddle.nn(functional and layer), test=develop

* fix hyperlinks in docstring

* add Conv/ConvTranspose layers in paddle.nn.layer, test=develop

* add example code in docstring, test=develop

* update unittests to work with test_runner, test=develop

* add functional conv

* add test and doc for function convs, test=develop

* update ConvTransposeOp's InferShape and error message, test=develop

* define alias in paddle dir and paddle.nn dir test=develop

* define alias in paddle.nn.functional dir test=develop

* define alias in paddle.tensor.__init__.py test=develop