Annotate continuations with immutable fields
Adapt mcons to main in pycket-lang
Fake parameter
Mostly done with parameters.
Fix writing.
Fix some module references.
Fix translation. Add asserts till it type checks.
fix base name
re-parse after interpreting to get a clean AST
fix one of the bad cases of anf.

not sure the bug of spenser is gone
fix an interaction problem between fusion and pruning
Fix extend-parameterization for Vasily.
put arith_unaryadd into base class
various failing tests about edge cases in arithmetic
refactor binary arithmetic operations

approach: first convert the two arguments into a common class

before I introduce rationals, I don't want to need a quadratic number of
methods per arithmetic operation.
move complex methods down
implement a slow version of rationals
replace make_int with W_Bignum.frombigint
use arith_unarysub
add an XXX