[Kget] Error handling in KDE 4.5

[Lukas Appelhans]

Hey!

As anybody knows our error handling in KDE 4.4 is far from optimal... we leave 
the plugins pretty  much alone handling those errors (and not every plugin 
reports much...).

For 4.5 we should improve the situation...

So my idea was to add some setError(Job::Error, const QString &errorMessage); 
to the transfer-class, which would handle the notification + give solutions on 
how to solve the error...

For example...
our transfer does setError(Job::DiskFull, i18n("Your harddisk is running out 
of memory"));. With that information we automagically show the error in the 
GUI and show an option to 1) move the transfer's files to somewhere else and 
2) to continue downloading... (+ we could detect automagically if the user 
removes files from the disk and resume the transfer).

If anyone agrees on this solution we would need a set of errors and proper 
names for it...

Lukas