#44 Doesn't compile with gcc 4.1

[Bernhard Rosenkraenzer]

Current gplflash2 doesn't compile with gcc 4.1.
The first reason is fairly trivial -
LocalFontManager's constructor is defined incorrectly
(duplicate LocalFontManager:: specialization -- no
longer accepted by gcc 4.1).

The second is quite a bit harder to solve --
std::list iterators are no longer pointers, therefore
the NULL assignments/comparisons in as_sprite etc.
don't work anymore.

Attaching a patch.

[Bernhard Rosenkraenzer]

Fix