Resolve wxPython code generation for SVG, XMP and Animation files

[KeyWorksRW]

Description:

Currently, SVG, XMP and Animation images have to be external (animation images are currently broken until we decide how to handle these three types).

zlib.decompress(string) supposedly takes a compressed binary string and decompresses it into a string. That means we should be able to create a Base64 rendering of an SVG file and decompress it into an actual SVG string to hand to FromSVG.

If we can get zlib.decompress(string) to work, then we could also compress XMP files as well (we already compress SVG files). I think we're stuck with animation files being external unless we can figure out how to convert the results of zlib.decompress(string) to a stream.