Merge branch 'master' of https://github.com/Microsoft-CISL/REEF into yingdac-restart-complete-handler
Merge pull request #972 from Microsoft-CISL/yingdac-restart-complete-handler

Add driver restart completed handler.

Tested on YARN and locally.
Merge pull request #962 from Microsoft-CISL/yingdac-add-nameserverconfig

make nameserver information available on http server, add NameServerConfig
Merge branch 'master' of https://github.com/Microsoft-CISL/REEF into yingdac-allow-setting-of-jobsubmissiondirectory
Merge pull request #974 from Microsoft-CISL/yingdac-allow-setting-of-jobsubmissiondirectory

allow setting of jobsubmissiondirectory
Merge remote-tracking branch 'origin' into reef-bridge