allow passing context variables about cligen

[c-blake]

This could probably be done more simply by just lifting the generated parser() out of the parser-dispatcher scope into the global scope and having users just call dispatchGen and then parseAndDispatchFoo() or FooFromSeq(). I don't think calling the parser without also dispatching to the wrapped proc is as easy, though I'm not sure you actually need to do that.

[c-blake]

Also, I feel like the newly added mergeParams() may be a solution here with a little thought. I was waiting for some feedback on those interfaces before punching a new release version. You should really take a look at mergeParams().

[c-blake]

Also, proposal 1 seems like it mostly exists as the dispatchGen parameter I called suppress. You probably just need to default the proc parameters to something instead of the Nim-default-initialization. I feel like between suppress and just using outer scope variables to pass stuff around this is not a real issue, and proposal 2 is mostly a dup of #30 which at a minimum needs its own brand new dispatchGen. So, I'm closing this.

[c-blake]

(Also, see the new setByParse parameter which is also very close to your proposal 2, but without objects/new types).