AU: Class to perform delta updates.

A class to perform delta updates and the associated unittests. Also,
change the delta diff generator executable to be able to apply a
delta, which is handy for debugging.

TEST=Attached unit test, hand-tested on real build images
BUG=552

Review URL: http://codereview.chromium.org/1718001
diff --git a/graph_utils.h b/graph_utils.h
index 62ecfd5..fd602ea 100644
--- a/graph_utils.h
+++ b/graph_utils.h
@@ -17,12 +17,12 @@
 namespace graph_utils {
 
 // Returns the number of blocks represented by all extents in the edge.
-uint64 EdgeWeight(const Graph& graph, const Edge& edge);
+uint64_t EdgeWeight(const Graph& graph, const Edge& edge);
 
 // block must either be the next block in the last extent or a block
 // in the next extent. This function will not handle inserting block
 // into an arbitrary place in the extents.
-void AppendBlockToExtents(std::vector<Extent>* extents, uint64 block);
+void AppendBlockToExtents(std::vector<Extent>* extents, uint64_t block);
 
 }  // namespace graph_utils