Split out ntpleapfetch

[Hal Murray]

I think we should remove ntpleapfetch from the main package and tarball - 
probably move it off to a separate package.

Leaf sites shouldn't need it.  They can get the leap-tonight from their 
upstream servers.

Many sites that do need it can get it from their distro.  We should encourage 
distros to package it their time zone data.

It has too high a chance of turning into a DDoS on the web servers providing 
leap-seconds.list.

-- 
These are my opinions.  I hate spam.