recursive copy had a bug with relative local paths.
this fixes that bug and changes the test framework
to use more of the code that actually runs in uplink
and only mocks out the direct interaction with the
operating system.
Change-Id: I9da2a80bfda8f86a8d05879b87171f299f759c7e
If the cp command is executed with higher level of parallelism, it would
open more connections to storage nodes at the same time. Therefore, the
connection pool capacity should be expanded accordingly.
The pool capacity is set to 100 * parallelism.
Change-Id: Ia8b3ab6a99340d8cbb87a7b80c3354b2b21c1958