Add ability to install extra packages part of the upgrade process

[sagarun]

• An user/organization may need/want to install additional new packages part of the upgrade process.

[sagarun]

This feature may not be helpful for a broader audience but definitely helpful in an organization that uses kickstart files for installations and allows its users to upgrade between releases using fedup.

For example the organization might have added extra rpms in the new release and want its users to have the new rpms on the system after the upgrade using fedup.

[wgwoods]

Seems harmless enough, but what's it useful for?

If you just want it to install stuff that's new in the new release, that's what issue #23 is about - in theory, yum (and your organization) should be doing stuff with comps groups and/or Requires to pull in things that are suggested/required in the new release.

Are there other uses for this?

[wgwoods]

...This is fixed by commit 6341783, which adds the --add-install flag.