Avoid leaking gettext into the global namespace
Update to OpenSeadragon v0.9.130

This adds support for image rotation:

https://github.com/openseadragon/openseadragon/issues/88
Add support for OpenSeadragon viewport rotation
Ensure that UI controls are synced on start

This is unnecessary if you're generating HTML server-side with the
correct initial values but is important for static files like our
examples.
Update examples to support URL history

This stores the current group/index in the URL hash to restore state on
load.