Update pub to use new import syntax.

utils/pub/version_solver.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.
 
 /**
  * Attempts to resolve a set of version constraints for a package dependency
  * graph and select an appropriate set of best specific versions for all
  * dependent packages. It works iteratively and tries to reach a stable
  * solution where the constraints of all dependencies are met. If it fails to
  * reach a solution after a certain number of iterations, it assumes the
@@ skipping 17 matching lines @@
  *
  * When a constraint on a package changes, we re-calculate the overall
  * constraint on that package. I.e. with a shared dependency, we intersect all
  * of the constraints that its depending packages place on it. If that overall
  * constraint changes (say from "<3.0.0" to "<2.5.0"), then the currently
  * picked version for that package may fall outside of the new constraint. If
  * that happens, we find the new best version that meets the updated constraint
  * and then the change the package to use that version. That cycles back up to
  * the beginning again.
  */
-#library('version_solver');
+library version_solver;
 
-#import('dart:json');
-#import('dart:math');
-#import('lock_file.dart');
-#import('package.dart');
-#import('pubspec.dart');
-#import('root_source.dart');
-#import('source.dart');
-#import('source_registry.dart');
-#import('utils.dart');
-#import('version.dart');
+import 'dart:json';
+import 'dart:math';
+import 'lock_file.dart';
+import 'package.dart';
+import 'pubspec.dart';
+import 'root_source.dart';
+import 'source.dart';
+import 'source_registry.dart';
+import 'utils.dart';
+import 'version.dart';
 
 /**
  * Attempts to select the best concrete versions for all of the transitive
  * dependencies of [root] taking into account all of the [VersionConstraint]s
  * that those dependencies place on each other and the requirements imposed by
  * [lockFile]. If successful, completes to a [Map] that maps package names to
  * the selected version for that package. If it fails, the future will complete
  * with a [NoVersionException], [DisjointConstraintException], or
  * [CouldNotSolveException].
  */
@@ skipping 663 matching lines @@
   final description1;
   final description2;
 
   DescriptionMismatchException(this.package, this.description1,
       this.description2);
 
   // TODO(nweiz): Dump to YAML when that's supported
   String toString() => "Package '$package' has conflicting descriptions "
     "'${JSON.stringify(description1)}' and '${JSON.stringify(description2)}'";
 }