Add the "Common European Cylinders" as per Henrik

This is Henrik's list of common metric sized cylinders, although my
experience differs from this one.  In Cyprus, I was diving double 12L
cylinders, but they were 200 bar, not the 232 bar ones Henrik has on the
list.

Also, I really think we should just have a checkbox for "double" instead
of naming them explicitly like this.  Henrik does have the 12L 200 bar
ones in his singles list.

But as a stop-gap, I'm just taking the values from Henrik's patch, but
converted to the new cleaned-up reference tank model setup.

Based-on-patch-by: Henrik Brautaset Aronsen <subsurface@henrik.synth.no>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

equipment.c

@@ -479,6 +479,17 @@ static struct tank_info {
 	{ "HP119", .cuft = 119, .psi = 3442 },
 	{ "HP130", .cuft = 130, .psi = 3442 },
 
+	/* Common European steel cylinders */
+	{ "10L 300 bar",  .ml = 10000, .bar = 300 },
+	{ "12L 200 bar",  .ml = 12000, .bar = 200 },
+	{ "12L 232 bar",  .ml = 12000, .bar = 232 },
+	{ "12L 300 bar",  .ml = 12000, .bar = 300 },
+	{ "15L 200 bar",  .ml = 15000, .bar = 200 },
+	{ "15L 232 bar",  .ml = 15000, .bar = 232 },
+	{ "D7 300 bar",   .ml = 14000, .bar = 300 },
+	{ "D8.5 232 bar", .ml = 17000, .bar = 232 },
+	{ "D12 232 bar",  .ml = 24000, .bar = 232 },
+
 	/* We'll fill in more from the dive log dynamically */
 	{ NULL, }
 };