adding and simplifying encoders/decoders

* make consistent between mri and jruby
* create a #to_h and have it use symbols for keys
* add #to_json and #to_proto helpers on the Google::Protobuf message classes
diff --git a/ruby/lib/google/protobuf.rb b/ruby/lib/google/protobuf.rb
index 7279724..99b1792 100644
--- a/ruby/lib/google/protobuf.rb
+++ b/ruby/lib/google/protobuf.rb
@@ -28,6 +28,9 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+# require mixins before we hook them into the java & c code
+require 'google/protobuf/message_exts'
+
 if RUBY_PLATFORM == "java"
   require 'json'
   require 'google/protobuf_java'
@@ -36,3 +39,25 @@
 end
 
 require 'google/protobuf/repeated_field'
+
+module Google
+  module Protobuf
+
+    def self.encode(msg)
+      msg.to_proto
+    end
+
+    def self.encode_json(msg)
+      msg.to_json
+    end
+
+    def self.decode(klass, proto)
+      klass.decode(proto)
+    end
+
+    def self.decode_json(klass, json)
+      klass.decode_json(json)
+    end
+
+  end
+end
diff --git a/ruby/lib/google/protobuf/message_exts.rb b/ruby/lib/google/protobuf/message_exts.rb
new file mode 100644
index 0000000..e10266b
--- /dev/null
+++ b/ruby/lib/google/protobuf/message_exts.rb
@@ -0,0 +1,53 @@
+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+# https://developers.google.com/protocol-buffers/
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+module Google
+  module Protobuf
+    module MessageExts
+
+      #this is only called in jruby; mri loades the ClassMethods differently
+      def self.included(klass)
+        klass.extend(ClassMethods)
+      end
+
+      module ClassMethods
+      end
+
+      def to_json
+        self.class.encode_json(self)
+      end
+
+      def to_proto
+        self.class.encode(self)
+      end
+
+    end
+  end
+end