Convert CMake-language commands to lower case

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

Modules/CMakeTestJavaCompiler.cmake

@@ -17,4 +17,4 @@
 # and link the most basic of programs.   If not, a fatal error
 # is set and cmake stops processing commands and will not generate
 # any makefiles or projects.
-SET(CMAKE_Java_COMPILER_WORKS 1 CACHE INTERNAL "")
+set(CMAKE_Java_COMPILER_WORKS 1 CACHE INTERNAL "")