Update corelib/ and lib/ to use the new try-catch syntax.

lib/json/json.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #library("dart:json");
 
 #import('dart:math');
 
 // Pure Dart implementation of JSON protocol.
 
@@ skipping 106 matching lines @@
   static objectLength(String str) {
     var p = new _JsonParser._internal(str);
     var firstToken = p._token();
     if (firstToken != LBRACE) {
       return 0;
     }
     try {
       p._parseObject();
       assert(p.position <= p.length);
       return p.position;
-    } catch (var e) {
+    } catch (e) {
       return 0;
     }
   }
 
   _JsonParser._internal(String json)
       : json = json,
         length = json.length {
     if (tokens !== null) return;
 
     // Use a list as jump-table, faster then switch and if.
@@ skipping 147 matching lines @@
           case CHAR_T:
             c = TAB;
             break;
           case CHAR_U:
             if (position + 5 > length) {
               _error('Invalid unicode esacape sequence');
             }
             final codeString = json.substring(position + 1, position + 5);
             try {
               c = parseInt('0x${codeString}');
-            } catch (var e) {
+            } catch (e) {
               _error('Invalid unicode esacape sequence');
             }
             position += 4;
             break;
           default:
             _error('Invalid esacape sequence in string literal');
         }
       }
       charCodes.add(c);
       position++;
@@ skipping 242 matching lines @@
         first = false;
       });
       _sb.add('}');
       _seen.removeLast();
       return;
     } else {
       throw const JsonUnsupportedObjectType();
     }
   }
 }