[poppler] Filename vs FileName

[Albert Astals Cid]

PDF on KDE bug 217013 has a dictionary with a key named Filename instead 
FileName, so when converting to PS it crashes.

The question is should each time we look for the FileName key look for the 
Filename one if it fails? Or even more broad should we turn dictionary 
searches case insensitive? Or do not try to make it work?

I vote for add the Filename fallback search

Comments?

Albert