Change the python-devel BuildRequires to python-libs

We want a BuildRequires for the distutils module, since it's not in
the regular python package (surprise!), but python-libs is where it
actually lives. python-devel is more for Python/C stuff, and we don't
have any of that.
Merge pull request #36 from dashea/master

Change the python-devel BuildRequires to python-libs
make 'make archive' regenerate archive

If any file changes, we need a new archive - so list all the files that
are in the git repo as deps.
fedup.spec: add system-upgrade-generator

Forgot to add this to the specfile. This fixes #34.
bump version to 0.8.0

Also add changelog to specfile.
Fix upgrade-prep failure with newer fedup-dracut

/run/system-upgrade is a copy of a symlink to a directory, so '-f' is
the wrong test. We could use '-d', but if it was a relative symlink it
might now be broken, so just test to see if it's a symlink.
updates to SystemUpgrade.asciidoc

This mostly includes some proposed (but not yet implemented) fixes for the
'preboot' script hook, and a few formatting changes.
update TODO file

The SELinux stuff was dropped since the SELinux guys assure me that:

a) the old system should always be compatible with the new policy, and
b) if it isn't, that's a bug, and they'll fix it
fix UnboundLocalError with fedup --device

The Great Denaming accidentally made 'fedup.media' and a local variable
named 'media' collide. Rename the local variable to fix that.
Make sure we actually unmount .iso at exit

If we're exiting due to an exception or something (e.g.
KeyboardInterrupt) we still need to unmount the iso. Use the 'atexit'
module to make sure this happens as expected.

...we can't do it in the 'finally:' block, sadly - if you try it there
the umount fails because yum/rpm stuff still has some .rpm file open.
fix missing local variables in media.py

There was a reference to 'log' but we weren't importing logging, and we
were referring to 'e' in an exception block that didn't have 'as e:'.
Improve check for .iso on removable media

The given arg for --iso might be a relative path, or a bind-mount, or
some other craziness. Check what actual device it's on and see if that
device is removable.
Make instrepo use failovermethod='priority'

This makes instrepo work more like the regular fedora repos.
Add ability to install extra packages part of the upgrade process

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