Patch to make PartController::editDocument() more robust

[Victor Röder]

> Hi,
> 
> Some parts call editDocument() with just the filename, so I made 
> editDocument() check in the project's current file list to see if the file
> is 
> known. See attached patch.
> 
> Next we should probably promp the user to locate the real url when this
> method 
> fails, but I haven't written that yet.
> 
> Comments / ok to apply?

Seems to be okay. If no one commits it, I will hopefully commit it next
week.

Bye,
         Victor

-- 
+++ GMX - Mail, Messaging & more  http://www.gmx.net +++
NEU: Mit GMX ins Internet. Rund um die Uhr für 1 ct/ Min. surfen!