Add various dive fixups, and show pressure (if any) in the plot

Now the dive profile plot *really* needs some units.  The pressure is
just a random line otherwise.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dive.h

@@ -1,6 +1,9 @@
 #ifndef DIVE_H
 #define DIVE_H
 
+#include <stdlib.h>
+#include <time.h>
+
 /*
  * Some silly typedefs to make our units very explicit.
  *
@@ -143,4 +146,7 @@ static inline unsigned int dive_size(int samples)
 	return sizeof(struct dive) + samples*sizeof(struct sample);
 }
 
+extern struct dive *fixup_dive(struct dive *dive);
+extern struct dive *try_to_merge(struct dive *a, struct dive *b);
+
 #endif /* DIVE_H */