We will no longer support full documentation generation from executables
and will instead generate documentation with other tools. Disable (with
a warning left behind) the command-line options:
--copyright
--help-compatcommands
--help-full
--help-html
--help-man
Drop supporting code. Drop manual sections generation from executables.
Remove internal documentation construction APIs. Drop unused sections
See Also, Author, Copyright, Compat Commands, Custom Modules.
This converts the CMake license to a pure 3-clause OSI-approved BSD
License. We drop the previous license clause requiring modified
versions to be plainly marked. We also update the CMake copyright to
cover the full development time range.