Doxygen: Add CPack/IFW subdir to doxyfile.in INPUT section
Doxygen: Add STRIP_FROM_PATH variable to doxyfile.in

This helps to better perceive information
CPackIFW: Refactor and revise this generator

Split the monolithic cmCPackIFWGenerator source into three parts:
cmCPackIFWGenerator, cmCPackIFWInstaller, and cmCPackIFWPackage
to isolate the implementations somewhat.

Add a COMMON option to the cpack_ifw_configure_component command to make
the data component common to its parent group.

Change the default packaging method to ONE_PACKAGE_PER_COMPONENT.
This is not incompatible because the CPack IFW generator has not
yet been in a release.
Merge topic 'cpack-ifw-generator' into next

194b412b CPackIFW: Refactor and revise this generator
82382479 Doxygen: Add STRIP_FROM_PATH variable to doxyfile.in
3040ab8f Doxygen: Add CPack/IFW subdir to doxyfile.in INPUT section