Big merge from experimental to bleeding edge.

pkg/path/lib/path.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.
 
 /// A comprehensive, cross-platform path manipulation library.
 library path;
 
 import 'dart:io' as io;
 
 /// An internal builder for the current OS so we can provide a straight
@@ skipping 338 matching lines @@
   /// array. Example:
   ///
   ///     // Unix
   ///     builder.split('/path/to/foo'); // -> ['/', 'path', 'to', 'foo']
   ///
   ///     // Windows
   ///     builder.split(r'C:\path\to\foo'); // -> [r'C:\', 'path', 'to', 'foo']
   List<String> split(String path) {
     var parsed = _parse(path);
     // Filter out empty parts that exist due to multiple separators in a row.
-    parsed.parts = parsed.parts.filter((part) => part != '');
+    parsed.parts = parsed.parts.where((part) => !part.isEmpty).toList();
     if (parsed.root != null) parsed.parts.insertRange(0, 1, parsed.root);
     return parsed.parts;
   }
 
   /// Normalizes [path], simplifying it by handling `..`, and `.`, and
   /// removing redundant path separators whenever possible.
   ///
   ///     builder.normalize('path/./to/..//file.text'); // -> 'path/file.txt'
   String normalize(String path) {
     if (path == '') return path;
@@ skipping 302 matching lines @@
     // If there is no dot, or it's the first character, like '.bashrc', it
     // doesn't count.
     if (lastDot <= 0) return [file, ''];
 
     return [file.substring(0, lastDot), file.substring(lastDot)];
   }
 
   _ParsedPath clone() => new _ParsedPath(
       style, root, new List.from(parts), new List.from(separators));
 }