fixes #276, path manipulation issues on windows. Also fixes server mode

bin/devrun.dart

 #!/usr/bin/env dart
 // Copyright (c) 2015, 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.
 
 /// Runs io.js with dev_compiler's generated code.
 library dev_compiler.bin.devrun;
 
 import 'dart:io';
 
@@ skipping 21 matching lines @@
   CompilerOptions options = validateOptions(args, forceOutDir: true);
   if (options == null || options.help) {
     _showUsageAndExit();
   }
   if (options.inputs.length != 1) {
     stderr.writeln("Please only specify one input to run");
     _showUsageAndExit();
   }
   var runner = new V8Runner(options);
 
-  if (!await compile(options)) exit(1);
+  if (!compile(options)) exit(1);
 
   var files = await listOutputFiles(options);
   var startStatement = 'dart_library.start("${getMainModuleName(options)}");';
 
   // TODO(ochafik): Only generate the html when some flag is set.
   await _writeHtmlRunner(options, files, startStatement);
 
   // Give our soul (and streams) away to iojs.
   Process process = await runner.start(files, startStatement);
   stdin.pipe(process.stdin);
@@ skipping 17 matching lines @@
   ''');
 
   stderr.writeln(
       'Wrote $htmlOutput. It can be opened in Chrome Dev with the following flags:\n'
       '--js-flags="--harmony-arrow-functions '
       '--harmony-classes '
       '--harmony-computed-property-names '
       '--harmony-spreadcalls"'
       '\n');
 }