[poppler] Limiting font size

[Albert Astals Cid]

In pdf found at http://bugs.kde.org/show_bug.cgi?id=127512 there is a pdf that 
in page 2 requests this sizes for fonts

140000000000
100000000000
120000000000

That causes the computer too DIE because freetype tries to allocate a HUGE 
buffer for rendering the font.

The solution is limiting the font size we want to let the user draw. Some 
people suggested me limiting to the size of the allowed font to something in 
the range [size in points, page size in points * 10]

What do you say?

Albert