[changelog] adding new inclusions to 5.9 release.
[changelog] adding new inclusions to 5.9 release.

Wattpad/dd-agent,manolama/dd-agent,manolama/dd-agent,jyogi/purvar-agent,jyogi/purvar-agent,takus/dd-agent,takus/dd-agent,takus/dd-agent,Wattpad/dd-agent,cberry777/dd-agent,Wattpad/dd-agent,cberry777/dd-agent,jyogi/purvar-agent,manolama/dd-agent,cberry777/dd-agent,manolama/dd-agent,manolama/dd-agent,Wattpad/dd-agent,takus/dd-agent,takus/dd-agent,Wattpad/dd-agent,jyogi/purvar-agent,cberry777/dd-agent,cberry777/dd-agent,jyogi/purvar-agent