[all] Change in Mixer sources order (will allow the EXTRA_3POS option later)

[all] Change in Switches order (to match the Mixer sources order and save some flash)
[all] New menu in MODELSEL when a ROTARY_ENCODER_NAVIGATION enabled
[all] Add REs (short) and REl (long) in Custom Functions screen. Will be needed later to reset the Rotary Encoder (for example)

src/stock/board_stock.cpp

@@ -185,7 +185,7 @@ bool switchState(EnumKeys enuk)
       result = !(PINE & (1<<INP_E_ID2));
       break;
 
-#if 0
+#if defined(EXTRA_3POS)
     case SW_ID3:
       result = (calibratedStick[POT1+EXTRA_3POS-1] < 0);
       break;