* Support namespace in Nacos cluster/configuration

* Give Nacos default namespace as per config/registry

* Provide Consul dynamic configuration center implementation

* Add more unit tests

* Fix unit test

* Add more unit tests and remove unused file

* Remove redundant doc

* Add TTL E2E test

* Add to Jenkins stage and minor bugfix

* Upgrade e2e container version

* Polish and minor fix

* Polish

* support ACL

* support digest only

* support elasticsearch address configuration with http scheme.

* update logical.

* First commit

* Fix e2e test and some nits

* Documenting so11y and setting default values of it in dev env

* Add cluster-etcd-plugin

* add time series implementation configuration.

* add configuration-api.

shuod ${var_application_file} not \${var_application_file}

* Add ALS proto and receiver in envoy

* Update docker building of oap server

 * generating appliation.yml according to enviroment variables
 * adding Makefile to build binary and docker image

* Update ui docker

* Update docker-compose

* Update document

* Update document

* Merge from master

* Reset skywalking-ui

* Update submodule skywalking-ui

* Refactor kubernetes config

* Add ui image