Bug 688124 "/UserUnit is not supported, yet in PDF1.6"

Hi all,

I have just attached a proposed patch for bug 688124 "UserUnit 
not supported".

Please see http://bugs.ghostscript.com/show_bug.cgi?id=688124#c9 
for (lots of) details and the patch itself, and 
http://bugs.ghostscript.com/show_bug.cgi?id=688124#c9 for a 
test file specially crafted for testing the implementation.

The patch also fixes some related problems that stayed in the 
way while testing it, even if these are only partly connected 
to implementing UserUnit and could be considered separate bugs. 
For example, it fixes bug #688359, because UserUnit and 
-dPDFFitPage have similar implementations.

Sincerely yours,
Gh Savulescu