merging BN changes into nook/contrib
Merge BN changes and bug fixes into nook contrib branch
Merge remote-tracking branch 'origin/contrib-nook-partial' into contrib/nook

Conflicts:
	src/main/java/com/adobe/epubcheck/ctc/EpubNCXCheck.java
	src/test/resources/com/adobe/epubcheck/test/DTBook/Basic_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/css/font_encryption_adobe_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/css/font_encryption_unknown_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/opf/Epub2_marked_v3_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/opf/Epub3_marked_v2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/opf/Excessive_Spine_Items_epub2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/opf/Fallbacks_epub2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/opf/Mismatched_mimetypes_epub2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/opf/Missing_NAV_epub2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/opf/Missing_NCX_epub2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/opf/Missing_Spine_epub2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/opf/Missing_metadata_epub2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/opf/oebps12_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/package/interesting_paths_epub2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/package/missing_mimetype_file_epub2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/package/missing_ncx_file_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/scripts/epub2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/xhtml/html5_epub2_expected_results.json
	src/test/resources/com/adobe/epubcheck/test/xhtml/singleline_expected_results.json