VOL-4977 - Failure in voltha-protos verification job.

Makefile
--------
 o This patch contains prototyping.
 o Define DISTUTILS_DEBUG to enable verbose output from python pkg install.
 o Define DOCKER_DEBUG to enable docker --debug.
 o Added whitespace to improve make output readability.
 o Insert banner text into targets so they will announce themselves for logging.
 o Remove @/$(HIDE) from prototype generation so command will be visible.

makefiles/docker/include.mk
---------------------------
 o Conditionally test for stdin and explicity pass --tty so docker can pass back log output.

.gitignore
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Ignore the virtualenv directory.

Change-Id: If73870fec03eadef2671f3f2f33075d58327914d
6 files changed