Added using UnityEngine; to UpdateInputManager

using UnityEngine; needs to be added the the UpdateInputManager demo otherwise Unity throws an error saying "The type or namespace name `MonoBehaviour' could not be found. Are you missing a using directive or an assembly reference?"
Update README.md
Merge pull request #25 from RyanNielson/patch-1

Update README.md.
Optimizations to reduce per frame allocations (#26).
Merge branch 'develop' of github.com:pbhogan/InControl into develop
Don't check in Library folder.
Remove Library/* files from repo.
Possible fix for Window Store Apps (#27)
Merge branch 'refs/heads/develop'
Solution updates.