ah, my previous commit contained a test for a particular EPUB, now reverting back to the dynamic OPF prefix-driven registration of "rendition" namespace (sorry) see https://github.com/readium/readium-sdk/commit/eb4eaebb9a5a92f50d843cdd62c095d8d81187f6#diff-4
follow-up to https://github.com/readium/readium-sdk/commit/9a9c8d84ffd7b8d77d439dac8ac7c62ef5552b2d
ensures that the prefix is declared (programmatically) even when missing from OPF
Merge branch 'develop' into feature/ByteRangeStreams