scripts/mupdfwrap.py: simplified SWIG Director classes.
scripts/mupdfwrap.py: simplified SWIG Director classes.

Our Director class callbacks now call internal static functions in the
implementation, instead of static class functions. This removes verbose
internal implementation details from the class definition.

ArtifexSoftware/mupdf,ArtifexSoftware/mupdf,TamirEvan/mupdf,TamirEvan/mupdf,TamirEvan/mupdf,ArtifexSoftware/mupdf,ArtifexSoftware/mupdf,ArtifexSoftware/mupdf,TamirEvan/mupdf,TamirEvan/mupdf,ArtifexSoftware/mupdf,TamirEvan/mupdf,TamirEvan/mupdf,ArtifexSoftware/mupdf,TamirEvan/mupdf,ArtifexSoftware/mupdf