The bakery bakes the user context type into an object so that it
doesn't have to be specified over and over again. This ends up being a
nicer way of specifying the CLI parameters, except for the fact that
it requires a slightly odd comptime block construct due to `var` not
working at the top level for some reason (and `comptime var` also not
working).
The user can provide a context type and corresponding value that will
get passed into any executed callbacks. This allows for complex
behavior through side effects and provides a mechanism by which the
user can pass an allocator into argument handlers, etc.
There was also a lot of restructuring in this including a bit more
automagical behavior, like making parameters that wrap optional types
default to being optional. The start of automatic handler picking
(user overridable, of course) is in place as well.
Needing to specify the userdata context type makes things a bit more
verbose, and there's some other jank I'm interested in trying to
remove. I have some ideas, but I don't know how far I can go in my
abuse of the compiler.
However, this seems like it will be usable once I get around to writing
the help text generation.
