fix spelling mistakes

[seanbreckenridge]

Couple spelling mistake fixes patched back from my fork. These are all in comments.

Theres another spelling mistake here, (commited_dt -> committed_dt) but its part of the NamedTuple definition, so I didn't change it; just wanted to let you know incase you wanted to do something about it. (perhaps a @property wrapper to maintain backwards compatability? maybe thats pushing it)

[karlicoss]

Thanks!

perhaps a @Property wrapper to maintain backwards compatability?

Yep, I think this is the way to go with such things. This particular module is probably used by very few people, but I guess best not to break it unless absolutely necessary.

Also a deprecation warning would be nice, I was thinking of using something like https://github.com/tantale/deprecated library, or just vendorizing a small, simple decorator to avoid an extra core dependency.