Provide access to the Refs of a PlotCommit

This information is generally useful - have followed the
accessor pattern of 'children' and 'parents'

Change-Id: I79b3ddd6f390152aa49e6b7a4c72a4aca0d6bc72
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

org.eclipse.jgit/src/org/eclipse/jgit/revplot/PlotCommit.java

@@ -144,6 +144,29 @@ public class PlotCommit<L extends PlotLane> extends RevCommit {
 		return false;
 	}
 
+	/**
+	 * Get the number of refs for this commit.
+	 *
+	 * @return number of refs; always a positive value but can be 0.
+	 */
+	public final int getRefCount() {
+		return refs.length;
+	}
+
+	/**
+	 * Get the nth Ref from this commit's ref list.
+	 *
+	 * @param nth
+	 *            ref index to obtain. Must be in the range 0 through
+	 *            {@link #getRefCount()}-1.
+	 * @return the specified ref.
+	 * @throws ArrayIndexOutOfBoundsException
+	 *             an invalid ref index was specified.
+	 */
+	public final Ref getRef(final int nth) {
+		return refs[nth];
+	}
+
 	/**
 	 * Obtain the lane this commit has been plotted into.
 	 *