Changes:
- bugfix: cdb utility: check return value from close() too, when creating the
cdb file
- portability: cdb utility: ignore SIGXFSZ signal if defined, to be able to
clean up when exceeding file limit
- robustness: let cdb_make_start to lseek() to the zero position of file. This
ensures the file is seekable right at the start instead of at the very end,
too
- portability use SEE_SET macro instead of 0 for lseek()
- split out cdb_pack() into its own .c file
0643004835