Currently InstallDir is part of the interpreter, and is an Interpreter
object, which is then put in the Build object. This is a layering
violation, the interperter should have a Holder for build data. This
patch fixes that.
This is PEP8 convention for a const variable. Also, make the type
Mapping, which doesn't have mutation methods. This means mypy will warn
us if someone tries to change this.
This patches takes the options work to it's logical conclusion: A single
flat dictionary of OptionKey: UserOptions. This allows us to simplify a
large number of cases, as we don't need to check if an option is in this
dict or that one (or any of 5 or 6, actually).
Dylan Baker
Daniel Mensinger
Xavier Claessens