* support gradient merge with recompute, test=develop
test=develop

* refine fleetrun.ps_launch

* update fleet run for multi device support

* ps_graph support ps-gpu

* fix heter save

* add heter save unittest

* fix unittest & simple code

* update fleetrun

* fix fleetrun

* fix launch barrier

* fix role maker

* add paddlecloud rolemaker unittest

* rename heter_worker_device_guard

* fleet support non_distributed training in dygraph mode; test=develop

* add double grad for expand, test=develop

* add gloo initializer, test=develop

* set default value to strategy in distributed_optimizer test=develop

* test=develop, rm netifaces

* add gloo initializer, test=develop

* add get final strategy for user to print final strategy

* fix test_dist_fleet_heter_ctr & peformance update

* test=develop, bug fix

* rename communicator meet->BatchesCounter

* fix parame recv for sparse

* geo sparse init from pserver

* optimize init from pserver

* add large scale optimizer fuse(SGD/ADAM)

* rectification init_worker and exe.run startup program

* fix fleet util and gloo

* fix worker endpoints

* fix

* fix UT

* fix gloo

* fix gloo

* update gloo

* update gloo

* update gloo

* update gloo

* update gloo

* fix gloo wrapper for hdfs

* add file gloo and UT

* fix UT

* fix UT

* fix UT

* hide public method of RoleMaker

* fix UT

* GPU fleetrun support gloo

* parameterserver fleetrun support gloo

* add UT

* add UT

* fix UT

* fix get server endpoint

* fix get server endpoint

* fix UT

* hide public method of rolemaker

* hide public method of rolemaker

* hide public method of rolemaker

* Update test_fleet_rolemaker_new.py

* hide public method of rolemaker

* hide public method of rolemaker

* fix worker endpoints

* fix gloo wrapper for hdfs

* GPU fleetrun support gloo

* parameterserver fleetrun support gloo

* fix get server endpoint

* test=develop, util documents

* fix fleet dynamic-mode en-doc;test=develop

* add adaptivelsgd

* Todo fix the code to avoid the conflict.

* fix ports conflict when launching multi-nodes in paddlecloud;test=develop

* add DISTRIBUTED_TRAINER_ENDPOINTS env for cloud;test=develop

* fix strategy, test=develop

* fix can_apply

* rm auto from localsgd

* parameter_server_optimizer support auto_strategy

add lars to fleet meta optimizer

* refine launch and distributed repr string for print

* test=develop, add ps auto

* fix the localsgd

* add auto parallel L1 implementation
test=develop

support heter-xpu-ps

* fix doc

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* fix doc, test=develop

* update localsgd doc
test=develop

* update localsgd doc
test=develop

* fix fleet dgc amp doc, test=develop

* fix, test=develop

* fix async configs
Co-authored-by: Nliuyi05 <gavin1332@gmail.com>
Co-authored-by: NWangXi <wangxi16@baidu.com>
Co-authored-by: NseiriosPlus <tangwei12@baidu.com>