update broadcast op args

Inverse arguments, missing file in last PR

Cyphers/view

Add contrib/docker, for reference build environment and initial CI

tweak cmake settings to work better on mac

remove comment out line per review comments

Initial implementation of the plugin library

Added "make check_cpu" target.  Removed unused definitions from Makefile.  Added chown_files.sh to ngraph_cpp_cpu image, instead of creating new image.

Bob/style

Add a couple scripts from ngraph/contrib/docker.  chown_files.sh solves a file permissions problem involving mounted directories in docker images.