Support extracting more than one directory from the container filesystem

[exdx]

Right now, dcp only extracts one directory from the image, provided via a mandatory command-line argument. As a user, I want to extract multiple directories (for example, /manifests and /metadata) from the image in one invocation of dcp.

A/C:

• Support specifying multiple directories as command line arguments, either comma separated or space separated, and have dcp copy these multiple directories out

[exdx]

It may also be possible to simply run the command multiple times with different -c arguments, and not implement this natively.