local changes for HE
Merge remote branch 'upstream/develop' into develop

fixed config.py

Conflicts:
	salt/config.py
Merge remote branch 'upstream/develop' into develop
Merge remote branch 'upstream/develop' into develop
added minion_denied to pki-structure to easily find denied minions
serializers fix
aggregation fix
use serializers in state.file
implements sls renderer
implement sls external pillar
implement merging strategy into pillar
elasticsearch returner.

Dependencies:

- official elasticsearch python client
- jsonpickler.

configuration is defined in the master config file:

```yaml
ext_job_cahe: elasticsearch

elasticsearch:
    host: 'some.host.com:9200'
    index: 'salt'
    number_of_shards: 1 (optional)
    number_of_replicas: 3 (optional)
```
Reimplemented 'latest_version()' to fix #12663 and make it more readable + better debug-able.
Added preliminary documentation
correct master settings
add link to elasticsearch client library docs
fixed lint errors
Initial commit of a zookeeper concurrency control module
Add aliyun for salt cloud
Merge remote-tracking branch 'upstream/develop' into aliyun