Fix #963 Docker socket timeout
Make UnixSocketHandler as a local url opener only for the Docker check
Docker check try to get container disk size then fallback
Add socket timeout to Docker check
Merge branch 'fix_proxy'
Make Docker timeout fallback happen just once per instance
Don't raise Exception if no Docker containers are running, fix #980
Don't raise Exception if we fail to get some Docker croup info, fix #981
Make custom emitter work
Merge pull request #990 from skumargithub/master

Make custom emitter work
Merge branch 'master' of https://github.com/DataDog/dd-agent
Minors improvements to Docker check logic and compatibility
Merge pull request #988 from DataDog/docker-fix-timeout

Docker fix timeout
Fix test
Merge pull request #989 from DataDog/docker-less-exception

Less Exception with Docker check
Remove unused file
Merge branch 'master' of https://github.com/DataDog/dd-agent
Bump version to 4.4.0
Update change log
Log something when instance metadata collection is disabled