James Turner :
Here's a patch which refactors the 'plain' GPS code into a slightly
more manageable structure - i.e breaks the large update() method into
various sub-functions. I've tested the patch with B1900d, and things
seem to work as expected, but if anyone experiences GPS weirdness
after this is committed, of course please report it.
The motivation for this was helping me learn the code - I've planning
some changes in this area, and splitting up the logic will hopefully
make that task easier.