Don't use xmlMode to normalize html

lib/utils/page.js

@@ -78,7 +78,7 @@ function pregQuote( str ) {
 
 // Adapt an html snippet to be relative to a base folder
 function normalizeHtml(src, options) {
-    var $ = cheerio.load(src, { xmlMode: true});
+    var $ = cheerio.load(src, { xmlMode: false});
     var toConvert = [];
     var svgContent = {};
     var outputRoot = options.book.options.output;