Merge tag '1.0.11' into develop

Ensure sensible default for ordering pages (default: position)
ensure get_page doesnt raise an exception
fix pyflakes
trap value error only
Merge pull request #56 from praekelt/feature/issue-56-allow-get_page-to-return-None

allow get_page to return None
version bump
Merge branch 'release/1.0.12'