new ntpleapfetch

[Hal Murray]

> Let me know if the above source should be used instead and I'll make
> the merge request.

We shouldn't publish URLs in something that will get widely distributed/used 
without checking with the owner.

Plan B would be to host a copy of the file ourselves.  Then we can update it 
as appropriate and we can beef up the server if the load becomes significant.  
That's a commitment to long term service.

----------

Quirks in doc:
       ntpleapfetch will validate the file currently on the local system and
       if necessary, updates leap-second definition file.

That seems awkward.  "the file" isn't well specified.  The tense of validate doesn't match the tense of updates.  How about:
       ntpleapfetch will validate the leap second file on the local system and
       if appropriate, fetch and install a new version.


        If the file does not exist, is not valid, has expired, or is expiring
        soon, a new copy will be downloaded. If the new copy validates, it is
        installed and NTP is (optionally) restarted. 

It shouldn't be restarted.  Sending ntpd a SIGHUP will check for a new copy.


-- 
These are my opinions.  I hate spam.