Add an examples getter for all Message objects in Intl

pkg/intl/lib/src/intl_message.dart

Index: pkg/intl/lib/src/intl_message.dart
diff --git a/pkg/intl/lib/src/intl_message.dart b/pkg/intl/lib/src/intl_message.dart
index 13aad6248562b233564c31adb0dabd00b05b121f..24290d2c9088a3e1fc85ba8f08baf0ecea7708d8 100644
--- a/pkg/intl/lib/src/intl_message.dart
+++ b/pkg/intl/lib/src/intl_message.dart
@@ -61,6 +61,12 @@ abstract class Message {
    */
   get arguments => parent == null ? const [] : parent.arguments;
 
+  /**
+   * We find the examples from the top-level [MainMessage] and use those

[Emily Fortuna, 2014/01/09 23:10:32]

does this comment make sense, because according to line 50, [MainMessage] is not
contained inside a parent...

[Alan Knight, 2014/01/10 18:44:28]

But MainMessage has an examples field that overrides this. Added a line to the
comment to clarify.

+   * when writing out variables.
+   */
+  get examples => parent == null ? const [] : parent.examples;
+
   String checkValidity(MethodInvocation node, List arguments,
                        String outerName, FormalParameterList outerArgs) {
     var hasArgs = arguments.any(