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.
Applying patch provided in issue #7797.
Fixes to man-pages:
- Character '-' must be espaced as '\-'
- Surround preformatted text with '.nf' and '.fi' to adjust filling
- Give every page a NAME section for indexing by mandb
- Pass the man page filename without extension to .TH in its header
Also added a title to the HTML header.