Dart textmate bundle updates (support for 'external' and 'as').

tools/utils/textmate/Dart.tmbundle/Syntaxes/Dart.textmate

 {       scopeName = 'source.dart';
         fileTypes = ( 'dart' );
         foldingStartMarker = '\{\s*$';
         foldingStopMarker = '^\s*\}';
         patterns = (
                 {       name = 'meta.preprocessor.script.dart';
                         match = '^(#!.*)$';
                 },
                 {       name = 'meta.declaration.dart';
                         begin = '#\b(library|import|source|resource)\b';
@@ skipping 42 matching lines @@
                                 {       name = 'variable.language.dart';
                                         match = '\b(this|super)\b';
                                 },
                                 {       name = 'constant.numeric.dart';
                                         match = '\b((0(x|X)[0-9a-fA-F]*)|(([0-9]+\.?[0-9]*)|(\.[0-9]+))((e|E)(\+|-)?[0-9]+)?)\b';
                                 },
                         );
                 };
                 keywords = {
                         patterns = (
+                                {       name = 'keyword.cast.dart';
+                                        match = '\bas\b';
+                                },
                                 {       name = 'keyword.control.catch-exception.dart';
                                         match = '\b(try|catch|finally|throw)\b';
                                 },
                                 {       name = 'keyword.control.ternary.dart';
                                         match = '\?|:';
                                 },
                                 {       name = 'keyword.control.dart';
                                         match = '\b(break|case|continue|default|do|else|for|if|in|return|switch|while)\b';
                                 },
                                 {       name = 'keyword.control.new.dart';
@@ skipping 23 matching lines @@
                                 {       name = 'keyword.operator.arithmetic.dart';
                                         match = '(\-|\+|\*|\/|\~\/|%)';
                                 },
                                 {       name = 'keyword.operator.logical.dart';
                                         match = '(!|&&|\|\|)';
                                 },
                                 {       name = 'punctuation.terminator.dart';
                                         match = ';';
                                 },
                                 {       name = 'storage.modifier.dart';
-                                        match = '\b(static|final|native|abstract|const|class|interface)\b';
+                                        match = '\b(static|final|native|abstract|const|class|interface|get|set|operator|external)\b';
                                 },
                                 {       name = 'storage.type.primitive.dart';
                                         match = '\b(?:void|bool|num|int|double|Dynamic|var)\b';
                                 },
                         );
                 };
                 string-interp = {
                         patterns = (
                                 {       match = '\$((\w+)|\{(\w+)\})';
                                         captures = {
@@ skipping 52 matching lines @@
                                         patterns = (
                                                 {       name = 'invalid.string.newline';
                                                         match = '\n';
                                                 },
                                         );
                                 },
                         );
                 };
         };
 }