add factory_reset option and store region code in preferences

mesh.options

@@ -21,6 +21,7 @@
 
 *UserPreferences.wifi_ssid max_size:33
 *UserPreferences.wifi_password max_size:64
+*UserPreferences.region max_size:6
 
 # 256 bit or 128 bit psk key
 *ChannelSettings.psk max_size:32

mesh.proto

@@ -479,13 +479,23 @@ message RadioConfig {
      * will be a station */
     bool wifi_ap_mode = 14;
 
+    /// The region code for my radio (US, CN, EU433, etc...)
+    string region = 15;
+
+    /**
+    This setting is never saved to disk, but if set, all device settings will be
+    returned to factory defaults.  (Region, serial number etc... will be
+    preserved)
+    */
+    bool factory_reset = 100;
+
     // If true, radio should not try to be smart about what packets to queue to
     // the phone
-    // bool keep_all_packets = 100;
+    // bool keep_all_packets = 101;
 
     // If true, we will try to capture all the packets sent on the mesh, not
     // just the ones destined to our node.
-    // bool promiscuous_mode = 101;
+    // bool promiscuous_mode = 102;
 
     /**
     For testing it is useful sometimes to force a node to never listen to
@@ -493,7 +503,7 @@ message RadioConfig {
     in ignore_incoming will have packets they send droped on receive (by
     router.cpp)
     */
-    repeated uint32 ignore_incoming = 102;
+    repeated uint32 ignore_incoming = 103;
   }
 
   UserPreferences preferences = 1;