Counter cleanup

[Hal Murray]

I just pushed code that fixes the counter overflow problem, Issue #424.

I made a pass through the mode6 code and fixed various other counters too.  
If you can read it, it should be big enough.  The hit count in the MRU slots 
didn't get changed.  It will take a long sustained attack to overflow.

I also added the type uptime_t and fixed all the places I found that use it.

I could easily have missed something.  I doubt if I broke anything, but there 
is the possibility that I fat fingered an edit.

I removed a couple of casts that seemed like clutter to me.  They may have 
been there to avoid warning messages - maybe about a hidden sign/unsigned 
change when a signed int is passed to a procedure that takes an unsigned.  I 
couldn't trigger any warnings.  If you get them, please tell me what's going 
on.  I expect the right cleanup is something other then adding a cast.

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We still need to make a pass through the code to verify that all the received 
packet processing counters get bumped and/or that all the bail paths bump 
something.



-- 
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