Ensure CMAKE_DATA_DIR, CMAKE_DOC_DIR, and CMAKE_MAN_DIR are always
relative paths in CMake code, and set defaults accordingly. Use the
install() command instead of install_files() and install_targets().
This is more modern and also avoids stripping of the first character
from user-specified destinations.
While at it, fix the default destinations reported in the bootstrap
help.
The commit "Cleanup regular expressions" removed real include filter
expressions and replaced them with lines like
INCLUDE_REGULAR_EXPRESSION("^.*$")
that do no filtering. We simplify the change by removing the lines
altogether.
Some of our third-party utilities have licenses that require their
copyright and license notices to be distributed with binary forms. This
commit adds installation rules to include these notices with installed
CMake documentation.
