Updates pull request from Roman Tsypuk to convert the build system from

ant to gradle.  Removes linux and windows application launch scripts and
produces an executable jar with all resources included.

src/main/java/io/github/dsheirer/dsp/gain/GainController.java

@@ -0,0 +1,10 @@
+package io.github.dsheirer.dsp.gain;
+
+public interface GainController
+{
+	public abstract void increase();
+
+	public abstract void decrease();
+	
+	public abstract void reset();
+}