IDPF/epubcheck — pull request #454 by rdeltour (2014-09-08 23:01:26+00:00)
Title: Check XHTML Content Docs extensions in EPUB 3

* make sure the extension of XHTML Content Docs is '.xhtml', in `OPFChecker30`
* remove duplicate `checkItem()` call in `OPFChecker`
* Only report `HTM_014` for EPUB 2 (in `EpubHTML5StructureCheck`)
* Add a new test for `HTM_014a`
* Add a new test for `HTM_014`
* Fix existing tests

Fixes #447