61 Rotating Control Channel Support - P25 Decoder (#475)

* Initial work on add support for rotating control channels.

* Creates multiple frequency editor control.

* Updates channel source editor to allow user to select multi-frequency
configuration and add multiple frequencies.

* Adds full support for rotating control channels to the P25 channelizer.
Users define multiple frequencies in the channel source configuration.
The decoder monitors the state of the channel for a CONTROL state.  If
the state does not stay in the CONTROL state for a user-specified delay
value, then the decoder rotates to the next frequency in the list.  This
behavior continues until the decoder state once again changes to CONTROL.

This is NOT a 'scanner' feature.

build.gradle

@@ -1,3 +1,23 @@
+/*
+ * ******************************************************************************
+ * sdrtrunk
+ * Copyright (C) 2014-2019 Dennis Sheirer
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ * *****************************************************************************
+ */
+
 buildscript {
     repositories {
         jcenter()
@@ -55,6 +75,7 @@ dependencies {
     compile 'org.apache.axis:axis:1.4'
     compile 'com.fasterxml.jackson.dataformat:jackson-dataformat-xml:2.9.3'
     compile 'org.kordamp.ikonli:ikonli-javafx:2.1.1'
+    compile 'org.kordamp.ikonli:ikonli-swing:2.1.1'
     compile 'org.kordamp.ikonli:ikonli-fontawesome-pack:2.1.1'
     compile 'com.google.guava:guava:27.0-jre'    
 }