pkg/utf: fixed layout, added todos, updated docs and homepage pubspec links

pkg/utf/lib/src/utf/utf8.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.
 
 part of utf;
 
 const int _UTF8_ONE_BYTE_MAX = 0x7f;
 const int _UTF8_TWO_BYTE_MAX = 0x7ff;
 const int _UTF8_THREE_BYTE_MAX = 0xffff;
 
@@ skipping 51 matching lines @@
     bytes--;
   }
   return value;
 }
 
 /**
  * Encode code points as UTF-8 code units.
  */
 List<int> codepointsToUtf8(
     List<int> codepoints, [int offset = 0, int length]) {
-  _ListRange source = new _ListRange(codepoints, offset, length);
+  ListRange source = new ListRange(codepoints, offset, length);
 
   int encodedLength = 0;
   for (int value in source) {
     if (value < 0 || value > UNICODE_VALID_RANGE_MAX) {
       encodedLength += 3;
     } else if (value <= _UTF8_ONE_BYTE_MAX) {
       encodedLength++;
     } else if (value <= _UTF8_TWO_BYTE_MAX) {
       encodedLength += 2;
     } else if (value <= _UTF8_THREE_BYTE_MAX) {
@@ skipping 63 matching lines @@
 
 /**
  * Provides an iterator of Unicode codepoints from UTF-8 encoded bytes. The
  * parameters can set an offset into a list of bytes (as int), limit the length
  * of the values to be decoded, and override the default Unicode replacement
  * character. Set the replacementCharacter to null to throw an
  * ArgumentError rather than replace the bad value. The return value
  * from this method can be used as an Iterable (e.g. in a for-loop).
  */
 class Utf8Decoder implements Iterator<int> {
-  final _ListRangeIterator utf8EncodedBytesIterator;
+  // TODO(kevmoo): should this field be private?
+  final ListRangeIterator utf8EncodedBytesIterator;
   final int replacementCodepoint;
   int _current = null;
 
   Utf8Decoder(List<int> utf8EncodedBytes, [int offset = 0, int length,
       this.replacementCodepoint =
       UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) :
       utf8EncodedBytesIterator =
-          (new _ListRange(utf8EncodedBytes, offset, length)).iterator;
+          (new ListRange(utf8EncodedBytes, offset, length)).iterator;
 
 
-  Utf8Decoder._fromListRangeIterator(_ListRange source, [
+  Utf8Decoder._fromListRangeIterator(ListRange source, [
       this.replacementCodepoint =
       UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) :
       utf8EncodedBytesIterator = source.iterator;
 
   /** Decode the remaininder of the characters in this decoder
     * into a [List<int>].
     */
   List<int> decodeRest() {
     List<int> codepoints = new List<int>(utf8EncodedBytesIterator.remaining);
     int i = 0;
@@ skipping 88 matching lines @@
       return true;
     } else if (replacementCodepoint != null) {
       _current = replacementCodepoint;
       return true;
     } else {
       throw new ArgumentError(
           "Invalid UTF8 at ${utf8EncodedBytesIterator.position - j}");
     }
   }
 }