Update project authors statements to Dartino

src/vm/multi_hashset.h

-// Copyright (c) 2015, the Fletch project authors. Please see the AUTHORS file
+// Copyright (c) 2015, the Dartino 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.md file.
 
 #ifndef SRC_VM_MULTI_HASHSET_H_
 #define SRC_VM_MULTI_HASHSET_H_
 
 #include "src/vm/hash_map.h"
 
 namespace fletch {
 
@@ skipping 38 matching lines @@
     }
 
     this->Erase(it);
     return true;
   }
 };
 
 }  // namespace fletch
 
 #endif  // SRC_VM_MULTI_HASHSET_H_