ntpdig has been Pythonized

[Eric S. Raymond]

ntpdig has been Pythonized.  Please test.  Expect offsets to match the
C version but synch distances to be different; this version uses a more
up-to-date formula matching ntpd's.

Daniel, please take a bit of time to review the protocol handling and
error modeling. The computations of epsilon/delta/adjust in packet.py
and the filter checks for selecting and sorting good servers in
ntpdig, both deserve close scrutiny by someone who isn't me

The codebase size has now dropped to 63KLOC of C, only 27% of its
original size. Additionally, we have eliminated a major external
dependency - on libevent2, which was only used for sntp/ntpdig.  Among
other advantages, this will make building NTPsec on the Macintosh
rather simpler.
-- 
		<a href="http://www.catb.org/~esr/">Eric S. Raymond</a>

Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is
a well-armed lamb contesting the vote!
	-- Benjamin Franklin