The DESTINATION changed from share/aclocal to ${CMAKE_XDGDATA_DIR}/aclocal.

The latter fits more consistently with other third party integration
files.

The directory contains auxiliary support files for integration with
other tools, not documentation.

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.

Ancient CMake versions required upper-case commands.  Later command
names became case-insensitive.  Now the preferred style is lower-case.

Run the following shell code:

cmake --help-command-list |
grep -v "cmake version" |
while read c; do
    echo 's/\b'"$(echo $c | tr '[:lower:]' '[:upper:]')"'\(\s*\)(/'"$c"'\1(/g'
done >convert.sed &&
git ls-files -z -- bootstrap '*.cmake' '*.cmake.in' '*CMakeLists.txt' |
egrep -z -v '^(Utilities/cm|Source/kwsys/)' |
xargs -0 sed -i -f convert.sed &&
rm convert.sed

The orginal patch has been reworked in order to follow
CMake source tree layout habit.
Inspired-By: Igor Murzov <e-mail@date.by>