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/ \+$//'

Modules/FindBullet.cmake

@@ -29,7 +29,7 @@
 
 macro(_FIND_BULLET_LIBRARY _var)
   find_library(${_var}
-     NAMES 
+     NAMES
         ${ARGN}
      HINTS
         ${BULLET_ROOT}
@@ -68,7 +68,7 @@ _FIND_BULLET_LIBRARY(BULLET_SOFTBODY_LIBRARY        BulletSoftBody)
 _FIND_BULLET_LIBRARY(BULLET_SOFTBODY_LIBRARY_DEBUG  BulletSoftBody_Debug BulletSoftBody_d)
 
 
-# handle the QUIETLY and REQUIRED arguments and set BULLET_FOUND to TRUE if 
+# handle the QUIETLY and REQUIRED arguments and set BULLET_FOUND to TRUE if
 # all listed variables are TRUE
 include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
 FIND_PACKAGE_HANDLE_STANDARD_ARGS(Bullet DEFAULT_MSG