Add a patch, which disables a call to atexit() to register libjasper's
own clean-up routine (jas_cleanup). The call would be of limited
use anyway, as freeing memory at exit is useful only for tracking
down memory leaks. Removing the atexit call eliminates crashes in
ImageMagick and GraphicsMagick, when they are compiled with modules
support -- when a library is dlclosed, calling its cleanup routine is
When compiling with gcc, declare the routine with ``__attribute__
(destructor)'' as per kan's otherwise obnoxious and inflammatory
e-mails. This will make sure, the routine is invoked, when libjasper
is dlclosed(). The only known apps that do that are ImageMagick and
GraphicsMagick (when built with modules support). They both call
the routine explicitly anyway...
While here enable parallel build of jasper itself, and eliminate the
most threatening warnings.