[fixes #431] Fins default to instance count / fin count == 1

- Fixed init bug
- added unittests for fin count loading/saving/creation

core/src/net/sf/openrocket/rocketcomponent/FinSet.java

@@ -74,7 +74,7 @@ public abstract class FinSet extends ExternalComponent implements RingInstanceab
 	/**
 	 * Number of fins.
 	 */
-	protected int fins = 3;
+	protected int fins = 1;
 	
 	/**
 	 * Rotation about the x-axis by 2*PI/fins.

core/src/net/sf/openrocket/rocketcomponent/TrapezoidFinSet.java

@@ -39,7 +39,7 @@ public class TrapezoidFinSet extends FinSet {
 	
 	
 	public TrapezoidFinSet() {
-		this(3, 0.05, 0.05, 0.025, 0.03);
+		this(1, 0.05, 0.05, 0.025, 0.03);
 	}
 	
 	// TODO: HIGH:  height=0 -> CP = NaN

core/test/net/sf/openrocket/rocketcomponent/FinSetTest.java

@@ -22,6 +22,18 @@ import net.sf.openrocket.util.LineStyle;
 import net.sf.openrocket.util.BaseTestCase.BaseTestCase;
 
 public class FinSetTest extends BaseTestCase {
+
+	@Test
+	public void testMultiplicity() {
+		final TrapezoidFinSet trapFins = new TrapezoidFinSet();
+		assertEquals(1, trapFins.getFinCount());
+
+		final FreeformFinSet fffins = new FreeformFinSet();
+		assertEquals(1, fffins.getFinCount());
+		
+		final EllipticalFinSet efins = new EllipticalFinSet();
+		assertEquals(1, efins.getFinCount());
+	}
 	
 	@Test
 	public void testTrapezoidCGComputation() {