Three more patches around ntp_fp.h

[Achim Gratz]

Here's another cruft-removing series:

The first one simplifies dtolfp and lfptod under the assumption that
we're dealing with a (reasonably small) time offset.  The uses I've
found are like that, also things wouldn't work at all with NTP dates
since we'd coerce 64 bits into 53 bits.

http://repo.or.cz/ntpsec/local.git/patch/1a5475619bbe2140293b6cdb9e065d78690869ca

The second one removes the s_fp type which actually was only used in one
place and is not even needed there since the unsigned version yields the
same bit pattern.  The helper macros and functions which dealt with this
type have gone poof as well.  I've also added some more explanations to
tour.txt.  The remaining u_fp type is only really needed in struct pkt
for sending small offsets over the wire.  All other places that use FP
scaling already use plain integers.

http://repo.or.cz/ntpsec/local.git/patch/02744307d392c51d1d2bfa5ac46bc830ec7fff38

The third one re-introduces 16 bit scaling macros and uses it in the
places where they had been re-invented as multiplications and divisions
(one would hope the optimizer recognizes those, but we better state our
intent more clearly).

http://repo.or.cz/ntpsec/local.git/patch/f1f0eff741cccc094f933fc0c2664c2200842b75


Regards,
Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

SD adaptation for Waldorf rackAttack V1.04R1:
http://Synth.Stromeko.net/Downloads.html#WaldorfSDada