Add support for Copy Artifact project copy permissions

Since 1.30, Copy Artifact supports specifing the projects that are allowed
to copy artifacts for a given project in the general job properties.

Change-Id: I5a9de21f449e98d08ec9303d55021d6a661257d4
Merge "Add support for Copy Artifact project copy permissions"
Make all help text start with lowercase letter

to match "show this help message and exit" text from argparse.

Change-Id: I8d5a39e704a07b8b95ab530a72249fd62e42a480
Make overrideDefaultExcludes line into 3 lines

for improved readability.

Manually clean up some hard-to-read XML code in
jenkins_jobs/modules/publishers.py that was trying to do a lot on one
line.

Change-Id: Ica0065aae6f2fbaf8755bd8b5d3dea8c7d5a9cb0
Merge "Make overrideDefaultExcludes line into 3 lines"