b64 unicode literals for images

IPython/html/tests/casperjs/test_cases/nb_roundtrip.js

@@ -15,8 +15,8 @@ mime =  {
         "javascript" : "application/javascript",
     };
     
-var black_dot_jpeg="\"\"\"/9j/4AAQSkZJRgABAQEASABIAAD/2wBDACodICUgGiolIiUvLSoyP2lEPzo6P4FcYUxpmYagnpaG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\nEH//2Q==\"\"\"";
-var black_dot_png = '\"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA1BMVEUAAACnej3aAAAAAWJLR0QA\\niAUdSAAAAAlwSFlzAAALEwAACxMBAJqcGAAAAAd0SU1FB94BCRQnOqNu0b4AAAAKSURBVAjXY2AA\\nAAACAAHiIbwzAAAAAElFTkSuQmCC\"';
+var black_dot_jpeg="u\"\"\"/9j/4AAQSkZJRgABAQEASABIAAD/2wBDACodICUgGiolIiUvLSoyP2lEPzo6P4FcYUxpmYagnpaG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\nEH//2Q==\"\"\"";
+var black_dot_png = 'u\"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA1BMVEUAAACnej3aAAAAAWJLR0QA\\niAUdSAAAAAlwSFlzAAALEwAACxMBAJqcGAAAAAd0SU1FB94BCRQnOqNu0b4AAAAKSURBVAjXY2AA\\nAAACAAHiIbwzAAAAAElFTkSuQmCC\"';
 var svg = "\"<svg width='1cm' height='1cm' viewBox='0 0 1000 500'><defs><style>rect {fill:red;}; </style></defs><rect id='r1' x='200' y='100' width='600' height='300' /></svg>\"";
 
 // helper function to ensure that the short_name is found in the toJSON