Merge branch 'ceiling-plot'

This enables plotting the ceiling in deco dives and also adds the
necessary code to the uemis importer. The only other dive computer this
has been tested with the OSTC and that needs a libdivecomputer patch in
order to provide the deco/ceiling information to Subsurface.

Fixes #5

dive.h

@@ -233,6 +233,7 @@ struct event {
 	struct event *next;
 	duration_t time;
 	int type, flags, value;
+	gboolean deleted;
 	char name[];
 };
 
@@ -269,6 +270,7 @@ struct dive {
 	duration_t duration, surfacetime;
 	int visibility; /* 0 - 5 star rating */
 	temperature_t airtemp, watertemp;
+	pressure_t surface_pressure;
 	cylinder_t cylinder[MAX_CYLINDERS];
 	weightsystem_t weightsystem[MAX_WEIGHTSYSTEMS];
 	char *suit;