High fidelity renderer for YouTube XML annotations in .ass format

assnotations.py takes in a filename for XML annotations, and writes the converted ass script to stdout.
Script dimensions can be defined with --width and --height.

Not all annotation features are supported yet, but this should render most annotations accurately.
Support for more output formats (vtt, srt) is planned in the future.

AnnotationsRestored team for help with implementation details, including the speech_bubble function which is ported from their code.