Revise C++ coding style using clang-format

Run the `Utilities/Scripts/clang-format.bash` script to update
all our C++ code to a new style defined by `.clang-format`.
Use `clang-format` version 3.8.

* If you reached this commit for a line in `git blame`, re-run the blame
  operation starting at the parent of this commit to see older history
  for the content.

* See the parent commit for instructions to rebase a change across this
  style transition commit.

Source/cmAddExecutableCommand.h

@@ -26,25 +26,21 @@ public:
   /**
    * This is a virtual constructor for the command.
    */
-  virtual cmCommand* Clone()
-    {
-    return new cmAddExecutableCommand;
-    }
+  virtual cmCommand* Clone() { return new cmAddExecutableCommand; }
 
   /**
    * This is called when the command is first encountered in
    * the CMakeLists.txt file.
    */
   virtual bool InitialPass(std::vector<std::string> const& args,
-                           cmExecutionStatus &status);
+                           cmExecutionStatus& status);
 
   /**
    * The name of the command as specified in CMakeList.txt.
    */
-  virtual std::string GetName() const { return "add_executable";}
+  virtual std::string GetName() const { return "add_executable"; }
 
   cmTypeMacro(cmAddExecutableCommand, cmCommand);
 };
 
-
 #endif