agenda for breaking API/CLI changes (miniwdl 2.0)

[mlin]

Sharp edges in the API/CLI we'd like to change one day (no specific timeframe):

• Invert StdLib & EvalContext
• Context/options for typechecking (.check_quant)
• Context/options for coercion (source-relative path resolution; perform on coercion from String, not at myriad downstream points; also path canonicalization [../ etc.] on value initialization)
• Env
• Replace the coroutine-based task runtime plugin scheme with a simpler OOP API
• runtime => requirements (in AST)
• [de]virtualize_filename => path
• rationalization of internal _helper (underscore-named) function names...if module filename is underscore-named, then functions within needn't be if they're meant for use by other modules (but purely module-internal helper functions still should be)