submodule
removed arbitrary top/bottom "margins" for reflowable EPUB content documents
fixed library thumbnail image aspect ratio
fixes #90 (stacked details buttons)
addresses #91 (CSS cleanup)
fixes #93 (ARIA navigation role and labels)
fixed #71 (library thumbnails and grid not aligned and title overflow)
moving epubReadingSystem versioning to feature branch (see #63)
submodule
removed epubReadingSystem grunt task (was invoked from Travis)