Update unittest to new package layout.

tests/html/svg_1_test.dart

 #library('SVG1Test');
-#import('../../pkg/unittest/unittest.dart');
-#import('../../pkg/unittest/html_config.dart');
+#import('../../pkg/unittest/lib/unittest.dart');
+#import('../../pkg/unittest/lib/html_config.dart');
 #import('dart:html');
 
 // Test that SVG is present in dart:html API
 
 main() {
   useHtmlConfiguration();
 
   test('simpleRect', () {
       var div = new Element.tag('div');
       document.body.nodes.add(div);
       div.innerHTML = @'''
 <svg id='svg1' width='200' height='100'>
 <rect id='rect1' x='10' y='20' width='130' height='40' rx='5'fill='blue'></rect>
 </svg>
 ''';
 
     var e = document.query('#svg1');
     Expect.isTrue(e != null);
 
     SVGRectElement r = document.query('#rect1');
     Expect.equals(10, r.x.baseVal.value);
     Expect.equals(20, r.y.baseVal.value);
     Expect.equals(40, r.height.baseVal.value);
     Expect.equals(130, r.width.baseVal.value);
     Expect.equals(5, r.rx.baseVal.value);
   });
 }