Prior to this commit, if a box some how got on disk that had an
incorrect or invalid version number that did not match Gem::Version,
Vagrant would throw an exception when attempting to generate a list of
the boxes on disk. This commit fixes that by looking at the version from
the path generated, and shows a warning to the user about the box and
skips it from the list so they at least know about the problematic box
and can still get a list of boxes.
6b9cdb4e48