Fixed EPUB3 nav generation.
ContentModule interface finalized.
Merge branch 'feature/WinRT' of github.com:readium/readium-sdk into feature/WinRT

* 'feature/WinRT' of github.com:readium/readium-sdk:
  Epub3 check was not working
  Add project to package the Readium SDK as a Visual Studio Extension (VSIX) - Add call to the copy assets script
  Add project to package the Readium SDK as a Visual Studio Extension (VSIX)