Remove trailing whitespace from most CMake and C/C++ code

Our Git commit hooks disallow modification or addition of lines with
trailing whitespace.  Wipe out all remnants of trailing whitespace
everywhere except third-party code.

Run the following shell code:

git ls-files -z -- \
 bootstrap doxygen.config '*.readme' \
 '*.c' '*.cmake' '*.cpp' '*.cxx' \
 '*.el' '*.f' '*.f90' '*.h' '*.in' '*.in.l' '*.java' \
 '*.mm' '*.pike' '*.py' '*.txt' '*.vim' |
egrep -z -v '^(Utilities/cm|Source/(kwsys|CursesDialog/form)/)' |
egrep -z -v '^(Modules/CPack\..*\.in)' |
xargs -0 sed -i 's/ \+$//'

Source/cmSetTargetPropertiesCommand.h

@@ -17,7 +17,7 @@
 class cmSetTargetPropertiesCommand : public cmCommand
 {
 public:
-  virtual cmCommand* Clone() 
+  virtual cmCommand* Clone()
     {
       return new cmSetTargetPropertiesCommand;
     }
@@ -41,12 +41,12 @@ public:
     {
     return "Targets can have properties that affect how they are built.";
     }
-  
+
   /**
    *  Used by this command and cmSetPropertiesCommand
    */
-  static bool SetOneTarget(const char *tname, 
-                           std::vector<std::string> &propertyPairs, 
+  static bool SetOneTarget(const char *tname,
+                           std::vector<std::string> &propertyPairs,
                            cmMakefile *mf);
 
   /**
@@ -159,7 +159,7 @@ public:
         "part of the default build when you select \"Build Solution\"."
         ;
     }
-  
+
   cmTypeMacro(cmSetTargetPropertiesCommand, cmCommand);
 };