Update README with history and justification

Better explained the relationship between this project and joeyh's
github-backup. This isn't a port of github-backup, as it was written
from the ground up in Java using a disting API.
Update copyright holders

This is software developed exclusively at UW-Madison, thus it shouldn't
be copyrighted as an OME consortium product.
Update licenses

Ran mvn license:update-file-header. This updated all files to the new,
non-OME copyright holders, and bumped the copyright year to include
2014.
Update bsd license

Fixed the copyright year and holders for the included BSD license.