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/cmListFileCache.h

@@ -22,7 +22,7 @@
  */
 
 class cmMakefile;
- 
+
 struct cmListFileArgument
 {
   cmListFileArgument(): Value(), Quoted(false), FilePath(0), Line(0) {}
@@ -64,11 +64,11 @@ class cmListFileBacktrace: public std::vector<cmListFileContext> {};
 
 struct cmListFile
 {
-  cmListFile() 
-    :ModifiedTime(0) 
+  cmListFile()
+    :ModifiedTime(0)
     {
     }
-  bool ParseFile(const char* path, 
+  bool ParseFile(const char* path,
                  bool topLevel,
                  cmMakefile *mf);