Update SinusPulsator to accept "reverse" parameter

The "reverse" parameter allows the effect to begin in the applied state, progressing towards the unapplied state. Useful for ImageOverlayPulsate effect to fade out from an ImageOverlay effect.

nifty-core/src/main/java/de/lessvoid/nifty/tools/pulsate/provider/SinusPulsator.java

@@ -39,6 +39,11 @@ public class SinusPulsator implements PulsatorProvider {
    */
   private boolean cycle = true;
 
+  /**
+   * start the pulsator at 1 (true) or 0 (false).
+   */
+  private boolean reverse = false;
+
   /**
    * Initialize the Pulsator.
    *
@@ -53,6 +58,7 @@ public void initialize(@Nonnull final Properties parameter) {
       period = 1000.f;
     }
     this.cycle = Boolean.parseBoolean(parameter.getProperty("cycle", Boolean.toString(true)));
+    this.reverse = Boolean.parseBoolean(parameter.getProperty("reverse", Boolean.toString(false)));
   }
 
   /**
@@ -64,15 +70,10 @@ public void initialize(@Nonnull final Properties parameter) {
   @Override
   public float getValue(final long msTime) {
     long t = msTime - startTime;
-    if (cycle) {
-      return getSinusValue(t);
-    } else {
-      if (t > period * HALF) {
-        return 1.0f;
-      } else {
-        return getSinusValue(t);
-      }
-    }
+    if (!cycle && t > period * HALF)
+        return (reverse? 0.0f: 1.0f);
+    else
+	    return getSinusValue(t + (reverse? (long)(period * HALF): 0l));
   }
 
   /**