- fix else if -> elif
- Move hammer-based type lookups to runtime
  - Hammer types can't be looked up at load time, since the library is not loaded yet

- ASTManager helper class to hold the top node of the ast to be printed
- HDoParseRetBreakpoint
- ast printing commands
- Update BreakpointManager tests with HDoParseRetBreakpoint tests
- Add support in TopLevelParse to select a stack item for printing the AST node of

It has been moved to top-level-parse.py

Fix breakpoint_manager not using its own retq finding function

Looks like there's a lot of duplicated code for the refactor
to clean up.

Finally, instead of having to hardcode a constant, the length of
the code to disassemble in search of a RET instruction is discovered
at runtime.