Add RVDSS endpoint and client support#1666

nmdefries wants to merge 4 commits intoadd_rvdss_indicatorcmu-delphi/delphi-epidata:add_rvdss_indicatorfrom

ndefries/rvdss-endpointcmu-delphi/delphi-epidata:ndefries/rvdss-endpointCopy head branch name to clipboard