Handle SVG correctly in page normalization

Related to mathjax/MathJax-node#65

lib/utils/page.js

@@ -78,7 +78,14 @@ function pregQuote( str ) {
 
 // Adapt an html snippet to be relative to a base folder
 function normalizeHtml(src, options) {
-    var $ = cheerio.load(src, { xmlMode: false});
+    var $ = cheerio.load(src, {
+        // We should parse html without trying to normalize too much
+        xmlMode: false,
+
+        // SVG need some attributes to use uppercases
+        lowerCaseAttributeNames: false,
+        lowerCaseTags: false
+    });
     var toConvert = [];
     var svgContent = {};
     var outputRoot = options.book.options.output;