* modify cond while_loop to paddle.static.nn.cond
* modify crop_tensor to paddle.crop
* modify Variable to paddle.static.Variable
* remove nn.beam_search, nn.beam_search_decode, nn.gather_tree
* remove bpr_loss, center_loss, rank_loss, smooth_l1, teacher_student_sigmoid_loss, edit_distance, sampled_softmax_with_cross_entropy in nn.functional
* remove apis in nn.functional.learn_rate.py
* remove pool2d, pool3d, adaptive_pool2d, adaptive_pool3d in nn.functional
* remove apis in nn.functional.vision
* remove erf, soft_relu in nn.functional.activation
* remove apis in nn.functional.extension
* remove nn.functional.rnn
* remove hash from nn.functional.lod
* remove row_conv from nn.functional.extension
* remove one_hot, pad2d, pad_constant_like from nn.functional.common
* remove nn.gather_tree, nn.BilinearTensorProduct, nn.Pool2D, nn.Pad2D
* remove apis from optimizer.__init
* remove tensor.creation.fill_constant
* remove elementwise_mul in nn.functional.common and modify to paddle.multiply
* remove tensor.stat.reduce_mean
* remove reduce_all, reduce_any in tensor.logic
* remove apis in tensor.math
* remove apis in tensor.__init__
* remove has_inf, has_nan in tensor.search
* remove apis in framework.__init__
* remove apis in paddle.__init__
* remove apis in nn.functional.__init__
* modify removed alias apis to raw api in doc and unittests
* fix remove grid_sample bug
* modify removed alias apis to raw api in doc and unittests
* modify removed alias apis to raw api in doc and unittests
* modify removed alias apis to raw api in doc and unittests
* modify removed alias apis to raw api in doc and unittests
* modify removed alias apis to raw api in doc and unittests
* modify removed alias apis to raw api in doc and unittests
* delete alias api relastions in doc
* reserve paddle.compat, paddle.sysconfig
* remove unittest for paddle.reduce_all, paddle.reduce_any
* modify removed alias apis to raw api in doc and unittests
* recover paddle.save and paddle.load
* resolve conflicts
* fix sample code missing paddle.enable_static() bug
* fix sample code missing paddle.enable_static() bug
* fix to_string sample code error