Datagram 25 trip calculation: factor for W should probably be 4096

[marcobergman]

The factor 65536 in Knaufs description of datagram 25 would cause the trip to make big jumps. It occurs to me that 4096 is probably the right factor.

[marcobergman]

Come to think of it, it might as well be the other way around: that the factor for Z should be 65536 in the calculation of total. My log is at 2370 NM miles now, I'll let you know when I'm at 2^12. If W becomes 1 then, it means that Knaufs specs are inconsistent and the upper 2 bits of YY are always 0.