Connect preferences to the rest of the code

The biggest problem here was that bool has different sizes in C and C++
code. So using this in a structure shared between the two sides wasn't a
smart idea.

Instead I went with 'short', but that caused problems with Qt being to
smart for its own good and not doing the right thing when dealing with
'boolean' settings and a short value. This may be something in the way I
implemented things (as I doubt that something this fundamental would be
broken) but the workaround implemented here (explicitly using 0 or 1
depending on the value of the boolean) seems to work.

I also decided to get rid of the confusion of where gflow/gfhigh are
floating point (0..1) and when they are integers (0..100). We now use
integers anywhere outside of deco.c.

I also applied some serious spelling corrections to the preferences
dialog's ui file.

Finally, this enables the code that selects which partial pressure graph
to show.

Still to do: font size, metric/imperial logic

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

main.c

@@ -25,11 +25,14 @@ struct preferences default_prefs = {
 	.mod  = FALSE,
 	.mod_ppO2  = 1.6,
 	.ead  = FALSE,
+	.profile_dc_ceiling = TRUE,
 	.profile_red_ceiling  = FALSE,
 	.profile_calc_ceiling = FALSE,
 	.calc_ceiling_3m_incr = FALSE,
-	.gflow = 0.30,
-	.gfhigh = 0.75,
+	.gflow = 30,
+	.gfhigh = 75,
+	.font_size = 14.0,
+	.show_invalid = FALSE,
 #ifdef USE_GTK_UI
 	.map_provider = OSM_GPS_MAP_SOURCE_VIRTUAL_EARTH_HYBRID,
 #endif