Add a "forall" quantifier before rank-n-types

This is for compatibility with GHC Trac #4426
Add Eq and Ord instances to Completion.
Bump version to 0.7.1.3 and update changelog.
Merge pull request #6 from joneshf/master

Add Eq and Ord instances to Completion.
Merge pull request #4 from monoidal/patch-1

Add a "forall" quantifier before rank-n-types
Bump upper bound on `base` to accomodate GHC HEAD-to-become-7.10

base needed a major version bump due to AMP landing