/**
\example reorder.cpp

Sometimes you get a packet that you'd rather deal with later.  This
can happen for a number of reasons; an example could be if you are
expecting an ordered sequence of packets, but (for whatever reason)
occasionally packets arrive out of order.  If the out-of-order packet
could just be stored temporarily, until the missing packets ahead of
it had arrived, then everything could be handled smoothly.

The #Memory object and the SFBMemory::remember(const u8*) function
provide such an ability, as illustrated here.  If room is available,
\c Memory.remember(packet) makes a copy of its packet argument, stores
that copy internally, and arranges for reflexes to be triggered on the
copy some time in the future (between #loop() calls, typically).
(Like one's own unconscious memory, perhaps) there's no particular
timing or ordering guarantees about \e when remembered packets will be
recalled.

As an illustration, this sketch sends out packets containing steadily
increasing counts, but occasionally sends packets out of order.  When
the reflex handler detects a jump in the sequence, it simply remembers
the out-of-order packet(s), and reacts to them again later (when
hopefully all the missing prior pieces have arrived.

In this output sequence, the sketch has been running a while, and is
now outputting sequence numbers in the 90's, when another board is
detected, at its sequence 4:

\code
s91
Ln 68.000 (Re)starting at 4
Ln 68.001 Sequence 4
s92
Ln 69.001 Sequence 5
s93
Ln 70.002 Sequence 6
s94
Ln 71.005 Sequence 7
Ln 71.021 Sequence 8
Ln 71.041 Sequence 9
s95
Ln 72.004 Sequence 10
s96
Ln 73.008 Sequence 11
Ln 73.061 Sequence 12
s97
Ln 73.121 Sequence 13
Ln 73.141 Sequence 14
Ln 73.161 Sequence 15
Ln 74.006 Sequence 16
s98
Ln 75.007 Sequence 17
s99
Ln 76.008 Sequence 18
s100
Ln 77.009 Sequence 19
s103
s102
s101
Ln 78.012 Sequence 20
\endcode

This output and timing suggests that several runs of 's' packets (7-9,
11-12, 13-16) arrived out of order and were temporarily remembered, so
the sequence outputs continue in order.  (And note our 's103'-'s101'
being sent out of order, as well.)

 */
