Comment 27 for bug 820080

I ran into this when porting the update-notifier to libappindicator.

I link to a branch that fixes the behavior. The idea is that in the fallback it fallback to the non fallback icon.
Eh, the idea is that if there is no "-panel" icon, it just uses the regular icon name. That should provide full
backward compatibility plus apps can (if the want) provide different icons but it does not break the case
where there is no "-panel" version of the icon. This assumes that its better to have any icon then a "broken
image" icon.