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/ \+$//'

Tests/Tutorial/Step4/CMakeLists.txt

@@ -37,7 +37,7 @@ target_link_libraries (Tutorial  ${EXTRA_LIBS})
 
 # add the install targets
 install (TARGETS Tutorial DESTINATION bin)
-install (FILES "${PROJECT_BINARY_DIR}/TutorialConfig.h" 
+install (FILES "${PROJECT_BINARY_DIR}/TutorialConfig.h"
   DESTINATION include)
 
 # enable testing
@@ -49,7 +49,7 @@ add_test (TutorialRuns Tutorial 25)
 # does the usage message work?
 add_test (TutorialUsage Tutorial)
 set_tests_properties (TutorialUsage
-  PROPERTIES 
+  PROPERTIES
   PASS_REGULAR_EXPRESSION "Usage:.*number"
   )
 

Tests/Tutorial/Step4/MathFunctions/mysqrt.cxx

@@ -11,7 +11,7 @@ double mysqrt(double x)
     {
     return 0;
     }
-  
+
   double result;
 
   // if we have both log and exp then use them
@@ -19,7 +19,7 @@ double mysqrt(double x)
   result = exp(log(x)*0.5);
   fprintf(stdout,"Computing sqrt of %g to be %g using log\n",x,result);
 #else
-  double delta;  
+  double delta;
   result = x;
 
   // do ten iterations