-strip trailing whitespace

Alex
CPack add easy possibility to warn about CPACK_SET_DESTDIR

CPackNSIS will only warn but sooner or later it should error out
make default install component name configurable

Until now an unnamed component was always named "Unspecified".
Now this name is taken from the new cmake variable CMAKE_INSTALL_DEFAULT_COMPONENT_NAME,
which is initialized to "Unspecified". But it can now be set to something
project-specific, per directory

Alex
-add docs for ${CMAKE_INSTALL_DEFAULT_COMPONENT_NAME}

Alex
CPack add necessary check to detect/warns/error on ABSOLUTE DESTINATION

The [usually] wrong usage of absolute DESTINATION in INSTALL rules
keeps popping-up on the ML. We shall have some way to:
  1) easily detect it.
  2) forbids this for some CPack generator like NSIS
In fact it should certainly be forbidden for *any* generators
when used on Windows but we may implements that on top of the current
patch.
The patch ask the task to the generated cmake_install.cmake scripts.
Those scripts are a little bit more complicated with that but
iff there are absolute DESTINATION. This cost nothing if relative
DESTINATION are used.
Two new vars are introduced (and documented to handle that):
CPACK_WARN_ON_ABSOLUTE_INSTALL_DESTINATION
and
CPACK_ERROR_ON_ABSOLUTE_INSTALL_DESTINATION
Fix KWStyle warning
Use CPACK_xxx and CMAKE_xxx in a consistent way.

CMAKE_xxx vars are now used in the CMake-generated cmake_install.cmake
script while CPACK_xxx equivalent vars are used from within CPack.
CPack is responsible for getting/forwarding definitions of
CPACK_xxxx var corresponding to CMAKE_xxxx when invoking
CMake-generated install scripts.
As a consequence:
CMAKE_ABSOLUTE_DESTINATION_FILES
CMAKE_WARN_ON_ABSOLUTE_INSTALL_DESTINATION
CMAKE_ERROR_ON_ABSOLUTE_INSTALL_DESTINATION
may be used from outside CPack as well.
e.g.
cmake -DCMAKE_ERROR_ON_ABSOLUTE_INSTALL_DESTINATION=1 -P cmake_install.cmake
works as expected.
CPack allow RPM and DEB generator to be used on OSX.

More generally add the check for possible generator "activation" at
runtime depending on a generator specific check.
The dynamic behavior is currently implemented only for MacOS
and should be fully backward compatible for other system.

Inspired-By Tom Hughes <tomtheengineer@gmail.com>
Calm down Borland compiler warning about "always true"
ExternalProject: Fix 'make' builds with Ninja (#13159)

Fix the build command when Ninja is the CMake Generator, but the
external project is created for a project that does not use CMake but
does use "make".
Fortran: Follow <>-style includes (#13239)

Fortran sources that pass through the C preprocessor may use

 #include "header"

syntax or

 #include <header>

syntax.  CMake already follows the former.  Teach it to follow the
latter.
FindPythonLibs: Document cache variables (#13240)

Add information on how to change which install of Python is found
by CMake.
write_basic_package_version_file() now works with unset CMAKE_SIZEOF_VOID_P

This fixes #13241.
If CMAKE_SIZEOF_VOID_P is not set, either in the installed or in the
using project, don't check for it.

Alex
add test for #13241: empty SIZEOF_VOIDP in write_basic_package_version_file

Alex
Merge topic 'MakeDefaultInstallComponentNameConfigurable'

b71e731 -add docs for ${CMAKE_INSTALL_DEFAULT_COMPONENT_NAME}
7ced073 make default install component name configurable
b6fba35 -strip trailing whitespace
Merge topic 'CPackNSIS-warnDESTDIRandABSOLUTE'

4986d52 Use CPACK_xxx and CMAKE_xxx in a consistent way.
f90223c Fix KWStyle warning
47f0dbd CPack add necessary check to detect/warns/error on ABSOLUTE DESTINATION
6ba055b CPack add easy possibility to warn about CPACK_SET_DESTDIR
Merge topic 'CPack-activateRPM-DEB-onMacOS'

801ea70 Calm down Borland compiler warning about "always true"
2a34b57 CPack allow RPM and DEB generator to be used on OSX.
Merge topic 'ExternalProject-Ninja-superbuild'

c9097c7 ExternalProject: Fix 'make' builds with Ninja (#13159)
Merge topic 'fortran-include-angle'

ad21079 Fortran: Follow <>-style includes (#13239)
Merge topic 'FindPythonLibs-doc-cache-vars'

c5c9af5 FindPythonLibs: Document cache variables (#13240)