Ben Gamari authored Jun 16, 2015 and Ben Gamari committed Jun 16, 2015

Summary:
Today when reading through the users manual I noticed a few spelling issues.
This prompted me to run the document through ispell which turned up even more
issues. I've tried to be conservative here; most of the corrections are
misspellings and typos but in a few cases I've moved from American to British
orthography.

Test Plan: Read.

Reviewers: austin

Reviewed By: austin

Subscribers: bgamari, thomie

Differential Revision: https://phabricator.haskell.org/D925