These files will allow cmake based projects to find the
library using find_package(cJSON). If successful, they can
use CJSON_LIBRARIES and CJSON_INCLUDE_DIRS.
Other build systems can use a similar approach to pkg-config:
cmake --find-package -DNAME=cJSON -DCOMPILER_ID=GNU -DLANGUAGE=C -DCMAKE_PREFIX_PATH=<path-to-non-sytem-installation-path> -DMODE=LINK
or with MODE COMPILE or EXISTS.
