Log Message:
NSD 4.0.3

Bug Fixes:
- Fix nsd.db unclean close check.  Previous databases are considered
  unclean by the code and are created anew.
- Adds nsd.db larger than 400Tb check for sanity. Also test if
  filesize as documented in the file is correct.
- nsd waits for tasks to complete on stop, prevents nsd.db corruption.
- fix to not delete tmpdir too early in shutdown process.
- disabled udb checking functionality that made it very slow,
  this was enabled when enable-checking was turned on.