manyNM and dependencies

[aryairani]

added upToN and manyNM + tests. They require() n >= 0, m >= n.

changed manyN from foldLeft to recursive — could use a sanity check, will the trampolining in cons be enough to keep it from blowing the stack? Updated the test to try larger numbers (#7).

Because no longer using Range in manyN, manyN needs to require n >= 0; same with skipManyN which calls manyN. Updated both tests.

[tpolecat]

Hey sorry this took so long. Would you mind rebasing and reviewing your tests? I did a quick merge and manyNM was failing ... may have to do with the internals change although that would make me a little suspicious.

[aryairani]

I don't mind at all, but I probably won't be able to look at it right away.

[tpolecat]

Thanks, no hurry at all.

[tpolecat]

I'm going to close this just to get it off the list, but feel free to reopen if you want to hack on it some more.