improvements

- split the 'sortby' select field into two fields
- sort by average
- legend shows plotted and total values in the date range
- removed InlineDataSeries, because it was not used anymore

pdb-ui/src/test/java/org/lucares/pdbui/domain/DataSeriesStatsTest.java

@@ -0,0 +1,60 @@
+package org.lucares.pdbui.domain;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+
+import org.testng.Assert;
+import org.testng.annotations.DataProvider;
+import org.testng.annotations.Test;
+
+@Test
+public class DataSeriesStatsTest {
+	@DataProvider
+	public Object[][] providerAverage() {
+		final List<Object[]> result = new ArrayList<>();
+
+		{
+			final List<DataSeriesStats> stats = Arrays.asList(//
+					new DataSeriesStats(10, 0, 0, 5.0)//
+			);
+			final double expected = 5.0;
+			result.add(new Object[] { stats, expected });
+		}
+		{
+			final List<DataSeriesStats> stats = Arrays.asList(//
+					new DataSeriesStats(0, 0, 0, 5.0)//
+			);
+			final double expected = 0.0; // no values
+			result.add(new Object[] { stats, expected });
+		}
+
+		{
+			final List<DataSeriesStats> stats = Arrays.asList(//
+					new DataSeriesStats(10, 0, 0, 5.0), //
+					new DataSeriesStats(40, 0, 0, 1.0)//
+			);
+			final double expected = 1.8; // 90 / 50
+			result.add(new Object[] { stats, expected });
+		}
+		{
+			final List<DataSeriesStats> stats = Arrays.asList(//
+					new DataSeriesStats(5, 0, 0, 7.0), //
+					new DataSeriesStats(0, 0, 0, 5.0), // // no values
+					new DataSeriesStats(20, 0, 0, 2.0)//
+			);
+			final double expected = 3.0; // (35+40) / 25
+			result.add(new Object[] { stats, expected });
+		}
+
+		return result.toArray(new Object[0][]);
+	}
+
+	@Test(dataProvider = "providerAverage")
+	public void testAverage(final Collection<DataSeriesStats> stats, final double expected) {
+
+		final double actual = DataSeriesStats.average(stats);
+		Assert.assertEquals(actual, expected, 0.01);
+	}
+}