ATV Demod: implemented 16 FPS mode

debian/changelog

@@ -1,6 +1,6 @@
 sdrangel (3.3.2-1) unstable; urgency=medium
 
-  * ATV plugins: 405 lines mode
+  * ATV plugins: added 405 lines, 20 and 16 FPS  modes
   * ATV demodulator: added a scope panel in a tab combo with the TV screen
 
  -- Edouard Griffiths, F4EXB <f4exb06@gmail.com>  Wed, 22 Mar 2017 23:14:18 +0100

plugins/channelrx/demodatv/atvdemodgui.cpp

@@ -603,6 +603,9 @@ float ATVDemodGUI::getFps(int fpsIndex)
     case 2:
         return 20.0f;
         break;
+    case 3:
+        return 16.0f;
+        break;
     case 0:
     default:
         return 25.0f;

plugins/channelrx/demodatv/atvdemodgui.ui

@@ -456,6 +456,11 @@
           <string>20 Fps</string>
          </property>
         </item>
+        <item>
+         <property name="text">
+          <string>16 Fps</string>
+         </property>
+        </item>
        </widget>
       </item>
       <item>