More warning C4702: unreachable code

Change-Id: I55930c0579f624cbd9d26ac21e41445ea6ae089b

mdds/mdds_0.6.0-unreachable-code.patch

@@ -8,3 +8,21 @@
  }
  
  template<typename _String, typename _Flag>
+--- misc/mdds_0.6.0/include/mdds/multi_type_vector_trait.hpp	2012-07-19 05:09:49.000000000 +0200
++++ misc/build/mdds_0.6.0/include/mdds/multi_type_vector_trait.hpp	2012-07-24 09:22:04.396955159 +0200
+@@ -95,7 +95,6 @@
+         default:
+             throw general_error("create_new_block: failed to create a new block of unknown type.");
+     }
+-    return NULL;
+ }
+ 
+ base_element_block* element_block_func_base::clone_block(const base_element_block& block)
+@@ -123,7 +122,6 @@
+         default:
+             throw general_error("clone_block: failed to clone a block of unknown type.");
+     }
+-    return NULL;
+ }
+ 
+ void element_block_func_base::delete_block(base_element_block* p)