Bump upper bound on `base` to accomodate GHC HEAD-to-become-7.10

base needed a major version bump due to AMP landing
Derive Functor/Applicative for Win32/Draw backend

Signed-off-by: Austin Seipp <austin@well-typed.com>
Merge pull request #10 from hvr/pr-base48

Changes to accomodate GHC HEAD/7.10