Found via `codespell` and `grep`

Automate with:

find Tests -type f -print0 | xargs -0 perl -i -0pe \
's/set\(([a-zA-Z0-9_]+)(\s+)"\$\{\1\}([^"])/string(APPEND \1\2"\3/g'

* Do not define BEOS anymore (this includes workarounds which we don't
  need most of the time in Haiku, so we prefer opt-in IF(HAIKU) in the
  cmake files instead).
* On the other hand, do define UNIX (we are trying to be compliant) and
  HAIKU (there is still a number of things we don't do like the
  average UNIX clone)
* Do not use UnixPaths, as our filesystem hierarchy isn't anything like
  what it expects.
* Do not use -nostart, which the compiler doesn't know about anymore.
  This used to be an Haiku extension to gcc, and is equivalent to
  -shared which is the default gcc option.
* While "dl" functions are provided in libroot, this is always
  implicitly linked so there is no need to tell cmake about it.
* Forcing position-independent code is not needed, so remove it.
* On the other hand, include appropriate linker options for executables
  and shared libraries.
* Support for the two available compilers in Haiku (gcc2 and gcc4) and
  pick the right headers and libraries according to the currently
  selected one.
* With the adoption of the package manager, the directory layout was
  changed. Tell cmake where to look for header files and libraries.
* As we don't define BEOS anymore, enable the workaround we still need
  for HAIKU as well. This is the lack of a libm (it is part of the
  implicitly linked in libroot)

Applied-by: Rolf Eike Beer <eike@sf-mail.de>

Ancient versions of CMake required else(), endif(), and similar block
termination commands to have arguments matching the command starting the
block.  This is no longer the preferred style.

Run the following shell code:

for c in else endif endforeach endfunction endmacro endwhile; do
    echo 's/\b'"$c"'\(\s*\)(.\+)/'"$c"'\1()/'
done >convert.sed &&
git ls-files -z -- bootstrap '*.cmake' '*.cmake.in' '*CMakeLists.txt' |
egrep -z -v '^(Utilities/cm|Source/kwsys/)' |
egrep -z -v 'Tests/CMakeTests/While-Endwhile-' |
xargs -0 sed -i -f convert.sed &&
rm convert.sed

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

Our Git commit hooks disallow modification or addition of lines with
trailing whitespace.  Wipe out all remnants of trailing whitespace
everywhere except third-party code.

Run the following shell code:

git ls-files -z -- \
 bootstrap doxygen.config '*.readme' \
 '*.c' '*.cmake' '*.cpp' '*.cxx' \
 '*.el' '*.f' '*.f90' '*.h' '*.in' '*.in.l' '*.java' \
 '*.mm' '*.pike' '*.py' '*.txt' '*.vim' |
egrep -z -v '^(Utilities/cm|Source/(kwsys|CursesDialog/form)/)' |
egrep -z -v '^(Modules/CPack\..*\.in)' |
xargs -0 sed -i 's/ \+$//'

Everything covered by these tests is now covered by the KWSys
DynamicLoader test and the Plugin test.

This property was left from before CMake always linked using full path
library names for targets it builds.  In order to safely link with
"-lfoo" we needed to avoid having both shared and static libraries in
the build tree for targets that switch on BUILD_SHARED_LIBS.  This meant
cleaning both shared and static names before creating the library, which
led to the creation of CLEAN_DIRECT_OUTPUT to disable the behavior.

Now that we always link with a full path we do not need to clean old
library names left from an alternate setting of BUILD_SHARED_LIBS.  This
change removes the CLEAN_DIRECT_OUTPUT property and instead uses its
behavior always.  It removes some complexity from cmTarget internally.