Removed some left-over files. They have been deleted earlier, but their licensing headers re-appeared, probably as part of a botched PR.
Close the parent context in DefaultContextClosureHandler
The addresses #810 by closing the parent context in `DefaultContextClosureHandler`, if there is any.
Merge pull request #811 from Microsoft-CISL/weimer_810

Close the parent context in DefaultContextClosureHandler
Merge branch 'master' of https://github.com/Microsoft-CISL/REEF into juwang-httpServerDistributedShell