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/cmIfCommand.h

@@ -26,7 +26,7 @@ public:
                                  cmExecutionStatus &);
   virtual bool ShouldRemove(const cmListFileFunction& lff,
                             cmMakefile &mf);
-  
+
   std::vector<cmListFileArgument> Args;
   std::vector<cmListFileFunction> Functions;
   bool IsBlocking;
@@ -41,7 +41,7 @@ public:
   /**
    * This is a virtual constructor for the command.
    */
-  virtual cmCommand* Clone() 
+  virtual cmCommand* Clone()
     {
     return new cmIfCommand;
     }
@@ -52,7 +52,7 @@ public:
    */
   virtual bool InvokeInitialPass(const std::vector<cmListFileArgument>& args,
                                  cmExecutionStatus &);
-    
+
   /**
    * This is called when the command is first encountered in
    * the CMakeLists.txt file.
@@ -72,7 +72,7 @@ public:
     {
     return "Conditionally execute a group of commands.";
     }
-  
+
   /**
    * This determines if the command is invoked when in script mode.
    */
@@ -238,22 +238,22 @@ public:
       "7) The left and right hand arguments to AND OR are "
       "independently tested to see if they are boolean constants, if "
       "so they are used as such, otherwise they are assumed to be "
-      "variables and are dereferenced. \n"    
+      "variables and are dereferenced. \n"
       ;
     }
 
   // this is a shared function for both If and Else to determine if the
   // arguments were valid, and if so, was the response true. If there is
   // an error, the errorString will be set.
-  static bool IsTrue(const std::vector<std::string> &args, 
-    std::string &errorString, cmMakefile *mf, 
+  static bool IsTrue(const std::vector<std::string> &args,
+    std::string &errorString, cmMakefile *mf,
     cmake::MessageType &status);
-  
+
   // Get a definition from the makefile.  If it doesn't exist,
   // return the original string.
   static const char* GetVariableOrString(const char* str,
                                          const cmMakefile* mf);
-  
+
   cmTypeMacro(cmIfCommand, cmCommand);
 };