api/server: StatPath, ArchivePath, ExtractToDir
api/server: StatPath, ArchivePath, ExtractToDir

Adds http handlers for new API endpoints:

GET ContainersArchivePath
  Return a Tar Archive of the contents at the specified location in a
  container. Deprecates POST ContainersCopy. Use a HEAD request to stat
  the resource.

PUT ContainersExtractToDir
  Extract the Tar Archive from the request body to the directory at the
  specified location inside a container.

Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)

vdemeester/engine-api,thaJeztah/engine-api,jwhonce/engine-api,mikedougherty/engine-api,docker/engine-api,rhatdan/engine-api,msabansal/engine-api