Roll Observatory packages and add a roll script

packages/petitparser/lib/src/json/parser.dart

Index: packages/petitparser/lib/src/json/parser.dart
diff --git a/petitparser/lib/src/json/parser.dart b/packages/petitparser/lib/src/json/parser.dart
similarity index 76%
rename from petitparser/lib/src/json/parser.dart
rename to packages/petitparser/lib/src/json/parser.dart
index 340ac7edde5270ad540fee512bf8edfbff990d11..e1647cbb66a9e22862f6a44c2cf38eccb02ec2e6 100644
--- a/petitparser/lib/src/json/parser.dart
+++ b/packages/petitparser/lib/src/json/parser.dart
@@ -1,15 +1,11 @@
-part of json;
+part of petitparser.json;
 
-/**
- * JSON parser.
- */
+/// JSON parser.
 class JsonParser extends GrammarParser {
   JsonParser() : super(const JsonParserDefinition());
 }
 
-/**
- * JSON parser definition.
- */
+/// JSON parser definition.
 class JsonParserDefinition extends JsonGrammarDefinition {
   const JsonParserDefinition();
 
@@ -39,9 +35,9 @@ class JsonParserDefinition extends JsonGrammarDefinition {
   });
 
   stringPrimitive() => super.stringPrimitive().map((each) => each[1].join());
-  characterEscape() => super.characterEscape().map((each) => JSON_ESCAPE_CHARS[each[1]]);
-  characterOctal() => super.characterOctal().map((each) {
-    throw new UnsupportedError('Octal characters not supported yet');
+  characterEscape() => super.characterEscape().map((each) => jsonEscapeChars[each[1]]);
+  characterUnicode() => super.characterUnicode().map((each) {
+    var charCode = int.parse(each[1].join(), radix: 16);
+    return new String.fromCharCode(charCode);
   });
-
 }