Write Python bindings for CCExtractor

Extend Python to use CCExtractor's library to access subtitles. You should export as much of CCExtractor as possible. At a minimum, it should be able to

- Open and close input video streams.
- For an open stream, get the list of programs.
- For a selected program, get the subtitles in various easy to use structures. You need to provide access to the original representation (for example, if it's US TV subtitles then a grid for CEA-608, if it's European DVB subtitles then a bitmap) as well as the conversion to usual formats such as .srt.

While CCExtractor itself uses its own library (lib_ccx), we are not aware of any other program using the library directly (as opposed to running CCExtractor and getting the generated file). This means - it's likely you will also need to modify the library itself to make it “sane enough” for this project.