virttest.standalone_test: Disable default behavior when using -c

Due to a mistake on my part, I disregarded the option -c
when writing the new behavior of the test suite. Let's
disable all backing up of images, download of JeOS and
the such when using -c.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
virttest.standalone_test: If -c used, tags are shortnames

When using -c, all bets about how the suite is used are
off, as for the number of guests used and other details.

So, to avoid name collisions, ensure the test tag in case
we're using our own configuration is equal to the shortname,
not the special, trimmed down tag we use when not using -c.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
Revert "Unify Windows unattended files"

We got reports of Win 2008r2 not able to install after
this commit, so let's revert it.

This reverts commit df91845c97bb8ee8cacdec4aacdcbc24c9932a0c.
Merge pull request #1423 from autotest/fix-config-option

Fix config option