fixes #103 (audio soundtrack epub:type values)
https://github.com/readium/readium-js-viewer/issues/164 Removed previous attempted fix (thanks Ryan!), added missing pause() instruction to let the Media Overlay player resume playback after the skipped elements (which may trigger a switch to the following SMIL).
minor changes to polish-up #79 (pagination API): removed obsolete param doc, hiding spine.direction internals by calling the existing API method, updated Media Overlays comments to reflect API change in ReadiumSDK.Models.CurrentPagesInfo
ReadiumSDK.Models.CurrentPagesInfo constructor was not called with correct parameters! (follow-up to #79, no need for a separate issue)
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.
Fixes #108
(non-linear spine item / document pages navigation)
Fixes #111 set a max height on svg elements just like we do for images