IE8 Fixes

Resolves: 

* https://github.com/openannotation/annotator/issues/426
* https://github.com/openannotation/annotator/issues/425
* https://github.com/openannotation/annotator/issues/422
* https://github.com/openannotation/annotator/issues/421
* https://github.com/openannotation/annotator/issues/420
* https://github.com/openannotation/annotator/pull/412
* https://github.com/openannotation/annotator/issues/419
* https://github.com/openannotation/annotator/issues/418
* https://github.com/openannotation/annotator/issues/417
* https://github.com/openannotation/annotator/issues/416
Nice, thanks.