Rewrite pub's version solver.

sdk/lib/_internal/pub/test/hosted/offline_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library pub_tests;
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 
 main() {
@@ skipping 43 matching lines @@
       serveNoPackages();
 
       d.cacheDir({
         "foo": ["1.2.2", "1.2.3"]
       }, includePubspecs: true).create();
 
       d.appDir({"foo": ">2.0.0"}).create();
 
       pubCommand(command, args: ['--offline'], error:
           "Package foo has no versions that match >2.0.0 derived from:\n"
-          "- myapp 0.0.0 depends on version >2.0.0");
+          "- myapp depends on version >2.0.0");
     });
   });
 }