Fickling

Adds a modular API for analyses and analysis results, permitting sorting and filtering results.

- Adds static dataflow analysis
- Improved unused variable detection checks
- Improved opcode injection
- Minor bugfixes in opcode encoding
- Fixes a bug that can result in a dirty stack after opcode injection
- Programmatic support for stacked pickle files
- Improved handling and parsing of `__builtin__`s

Bugfix Release
Adds a workaround for an issue with a third party dependency affecting Python 3.8 and earlier.
Adds the `socket` module as an overtly unsafe import.

Improvements to documentation and examples, as well as support for two additional pickling opcodes.

Support for additional opcodes and minor bugfixes in AST generation.

This is the initial public release of Fickling.