I'm still working on reducing the size of the monster patches that I
land, but I'm exercising the priviledge as the initial author. In any
case, this refactors worker into two, and cleans up the passing around
of the processChan. This puts common code into Init and Close.
When creating new resources, we didn't specify the defaults, which for
the limit metaparam caused invalid resources by default. It would be
nice to change the limit param to have the 1/X (reciprocal) as the
default, although the problem with that is that (1) it is illogical, and
(2) it's not clear if the precision for the common cases is enough.
If someone wants to investigate this further, please do! Zero value
structs are definitely more useful! In any case, we can now specify the
default. It's not entirely obvious to me if this is the best way to do
it, or if there is a superior method.
Remove the New constructors since calling Init should be done by the
engine, and not by the user even when using mgmt as a lib. This is also
the case in tests! It used to be the case that a user might want to call
Init manually, but that is no longer the case!
