This update changes the plot to use a right y axis for speed. This makes it easier to see speed differences.
Some other packages use separate y axes for each data type, but as far as I can tell, this is not available with the qwt library used by GC.
--jtc
regardless of the Units preference. This patch checks the preference
and displays it in the appropriate units.
Unlike some of the other cases, I'm checking the value of the Units
setting each time the plot/panel is displayed.
The patch also pulls the 0.62137119 magic constant into a #define
MILES_PER_KM. This constant (and it's inverse, KMS_PER_MILE), occurs
in several files, and (IMHO) really deserves to be pulled into a
separate header, but again, that's work for another day.
--jtc
someone sets the date on their PT and doesn't reset the device before going
for a ride. This fix will keep GC working until the user splits the ride
(and until we add a ride-splitting function).
