Fix #16, only install user-level header files
Fix #15. Add edt local storage. The runtime must be configured with --enable-els=size. The api is accessible by including ocr-runtime-itf.h - This header is distributed only when enable-els has been passed at configure time.
Directly casting db_args to (void **) in the ocrDbCreate call causes a type-punning warning with gcc-4.1.2