Add support for --no-colors to make it easier to integrate dart2js in the editor.

lib/compiler/implementation/dart2js.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('dart2js');
 
 #import('dart:io');
 #import('dart:uri');
 #import('dart:utf');
 
 #import('../compiler.dart', prefix: 'api');
-#import('colors.dart');
+#import('colors.dart', prefix: 'colors');
 #import('source_file.dart');
 #import('filenames.dart');
 #import('util/uri_extras.dart');
 
 final String LIBRARY_ROOT = '../../../..';
 
 void compile(List<String> argv) {
   Uri cwd = getCurrentDirectory();
   bool throwOnError = false;
   bool showWarnings = true;
@@ skipping 14 matching lines @@
       String path =
           nativeToUriPath(argument.substring(argument.indexOf('=') + 1));
       if (!path.endsWith("/")) path = "$path/";
       libraryRoot = cwd.resolve(path);
     } else if (argument.startsWith('--out=')) {
       String path =
           nativeToUriPath(argument.substring(argument.indexOf('=') + 1));
       out = cwd.resolve(path);
     } else if ('--allow-mock-compilation' == argument) {
       options.add(argument);
+    } else if ('--no-colors' == argument) {
+      colors.enabled = false;
     } else if (argument.startsWith('-')) {
       fail('Unknown option $argument.');
     } else {
       arguments.add(nativeToUriPath(argument));
     }
   }
   if (arguments.isEmpty()) {
     fail('No file to compile.');
   }
   if (arguments.length > 1) {
@@ skipping 11 matching lines @@
     String source = readAll(uriPathToNative(uri.path));
     dartBytesRead += source.length;
     sourceFiles[uri.toString()] =
       new SourceFile(relativize(cwd, uri), source);
     Completer<String> completer = new Completer<String>();
     completer.complete(source);
     return completer.future;
   }
 
   void info(var message) {
-    if (verbose) print('${green("info:")} $message');
+    if (verbose) print('${colors.green("info:")} $message');
   }
 
   void handler(Uri uri, int begin, int end, String message, bool fatal) {
     if (uri === null && !fatal) {
       info(message);
       return;
     }
     if (uri === null) {
       assert(fatal);
       print(message);
@@ skipping 64 matching lines @@
     } catch (var ignored) {
       print('Internal error: error while printing exception');
     }
     try {
       print(trace);
     } finally {
       exit(253); // 253 is recognized as a crash by our test scripts.
     }
   }
 }