Revert "restored Ryan's original code as per #181 and https://github.com/readium/readium-shared-js/commit/e41a3cc4aa781aad7487a3228817c789f0e2b465"
Revert "restored Ryan's original code as per #181 and https://github.com/readium/readium-shared-js/commit/e41a3cc4aa781aad7487a3228817c789f0e2b465"

This reverts commit 65cf5f88483a0947e797a570ece91e71f5cc46e4.

bibliolabs/readium-shared-js,ravn-no/readium-shared-js,NYPL/readium-shared-js,readium/readium-shared-js,kivuto/readium-shared-js,AccessSeoul/readium-shared-js,ravn-no/readium-shared-js,bibliolabs/readium-shared-js,NYPL-Simplified/readium-shared-js,pmstss/readium-shared-js,dariocravero/readium-shared-js,NYPL-Simplified/readium-shared-js,readium/readium-shared-js,pmstss/readium-shared-js,JoMedia/readium-shared-js,AccessSeoul/readium-shared-js,bpyoung/readium-shared-js,kivuto/readium-shared-js,dariocravero/readium-shared-js,NYPL/readium-shared-js,bpyoung/readium-shared-js