485 Upgrade Project and Build to Java 11 (#496)

* Updates gradle to 5.1.1

* Updated to run application from intellij using installed Java 11.
Resolves issues with Java 9 deprecations.

* Updates gradle build dependencies and other deprecation issues.

* Updates gradle to produce OS-specific builds.

* Updates the beryx runtime plugin to 1.1.1 to resolve issue with zipping
each of the target distributions.

* Import cleanup

* Resolves issue with Look and Feel error on Max OSX
Resolves issue with building OSX package
Resolves issue with excessive logging about JMBE library.

src/main/java/io/github/dsheirer/gui/control/MultipleFrequencyEditor.java

@@ -451,7 +451,7 @@ public class MultipleFrequencyEditor extends JPanel
                 }
                 catch(Exception exc)
                 {
-                    return new Double(0);
+                    return 0.0d;
                 }
             }
         }