Roll Observatory packages and add a roll script

petitparser/lib/src/reflection/optimize.dart

-part of reflection;
-
-/**
- * Returns a copy of [parser] with all settable parsers removed.
- */
-Parser removeSettables(Parser parser) {
-  return transformParser(parser, (each) {
-    while (each is SettableParser) {
-      each = each.children.first;
-    }
-    return each;
-  });
-}
-
-/**
- * Returns a copy of [parser] with all duplicates parsers collapsed.
- */
-Parser removeDuplicates(Parser parser) {
-  var uniques = new Set();
-  return transformParser(parser, (source) {
-    var target = uniques.firstWhere((each) {
-      return source != each && source.isEqualTo(each);
-    }, orElse: () => null);
-    if (target == null) {
-      uniques.add(source);
-      return source;
-    } else {
-      return target;
-    }
-  });
-}