Change disint to also export a function which returns an expression and a list of operations it will perform; implement disint:-ModuleApply in terms of this function. Debug printing is removed from disint:-do, since it isn't really compatible with the new semantics (but such a change makes it possible to do 'first class' debugging! - as well as to easily replace the debugging info.  I prefer the first option, so I have chosen not to replace the debug printing)
Change disint to also export a function which returns an expression and a list
of operations it will perform; implement disint:-ModuleApply in terms of this
function. Debug printing is removed from disint:-do, since it isn't really
compatible with the new semantics (but such a change makes it possible to do
'first class' debugging! - as well as to easily replace the debugging info.  I
prefer the first option, so I have chosen not to replace the debug printing)

zaxtax/hakaru,zachsully/hakaru,zachsully/hakaru,zaxtax/hakaru