Change how to set the Dart name of a field

README.md

 Protoc compiler Dart plugin
 ===========================
 
 This application provides a plugin for protoc compiler which
 generates pure Dart library to deal with protobufs.
 
 Please, do not forget that generated libraries depend on runtime
 support library which can be found [here](https://github.com/dart-lang/dart-protobuf).
 
 How to build and use
@@ skipping 19 matching lines @@
 ### Options to control the generated Dart code
 
 The protocol buffer compiler accepts options for each plugin. For the
 Dart plugin, these options are passed together with the `--dart_out`
 option. The individial options are separated using comma, and the
 final output directive is separated from the options using colon. Pass
 options `<option 1>` and `<option 2>` like this:
 
     --dart_out="<option 1>,<option 2>:."
 
-#### Option for setting the name of field accessors
-
-The following message definition has the field name `has_field`.
-
-    message MyMessage {
-      optional string has_field = 1;
-    }
-
-This poses the problem, that the Dart class will have a getter and a
-setter called `hasField`. This conflicts with the method `hasField`
-which is already defined on the superclass `GeneratedMessage`.
-
-To work around this problem the option `field_name` can be
-used. Option `field_name` takes two values separated by the vertical
-bar. The first value is the full name of the field and the second
-value is the name of the field in the generated Dart code. Passing the
-following option:
-
-    --dart_out="field_name=MyMessage.has_field|HasFld:."
-
-Will generate the following message field accessors:
-
-    String get hasFld => getField(1);
-    void set hasFld(String v) { setField(1, v); }
-    bool hasHasFld() => hasField(1);
-    void clearHasFld() => clearField(1);
-
 Using protocol buffer libraries to build new libraries
 ------------------------------------------------------
 
 The protocol buffer compiler produces one library for each `.proto` file
 it compiles. In some cases this is not exactly what is needed, e.g one
 would like to create new libraries which exposes the objects in these
 libraries or create new librares combining object definitions from
 several `.proto` libraries into one.
 
 The best way to aproach this is to create the new libraries needed and
@@ skipping 59 matching lines @@
     $ protoc --plugin=protoc-gen-dart=./plugin --dart_out=. test.proto
 
 Useful references
 -----------------
 
 * [Main Dart site](http://www.dartlang.org)
 * [Main protobuf site](https://code.google.com/p/protobuf)
 * [Protobuf runtime support project](https://github.com/dart-lang/dart-protobuf)
 * [DartEditor download](http://www.dartlang.org)
 * [Pub documentation](http://pub.dartlang.org/doc)