Additions to fedora.css

[Toshio Kuratomi]

I'd like to make this change to fedora.css.  This adds some CSS that is
generally useful for Fedora Web Apps.  None of them were defined already
in fedora.css.  individual web apps are probably already overriding
these with their own css but over time we can remove those from the
individual apps and rely on the fedora.css more.

* Note: The three icons for the flash messages info.png, success.png,
and important.png aren't very good.  A real graphic designer could
probably do a lot better :-)

Should I do this or are there drawbacks?

-Toshio