added some notes about the new connection settings to README.md

(closes #44)

README.md

@@ -7,8 +7,8 @@ This repository provides a [Kodi] (http://kodi.tv) PVR addon for interfacing wit
 ### Settings
 
 This list contains some explanation for the non-obvious settings:
-* `HTTP and UPnP port`: You'll only need to change these from their respective defaults if you wish to use a VBox TV Gateway over the Internet and you're using asymmetric port forwarding (e.g. port 8080 -> 80 and 12345 -> 55555). The HTTP port is used to communicate with the device while the UPnP port is used when streaming media.
-* `External XMLTV path`: The addon can augment the EPG data it receives from the VBox device with external data in XMLTV format. This option is for specifying the path to the XML file that holds the guide data. It is your responsibility to make sure this file is updated on a regular basis.
+* `Connection`: There are two tabs in the settings dialog with identical settings, which means you can configure your addon to contact the VBox TV Gateway using both its internal and external address/port. This is useful for e.g. a laptop which is not permanently inside your internal network. When the addon starts it first attempts to make a connection using the internal settings. If that fails, it will try the external settings instead. The addon restarts itself if the connection is lost so it will automatically switch back without having to restart Kodi.
+  * `HTTP and UPnP port`: You'll only need to change these from their respective defaults if you wish to use a VBox TV Gateway over the Internet (i.e. the external connection settings tab) and you're using asymmetric port forwarding (e.g. port 8080 -> 80 and 12345 -> 55555). The HTTP port is used to communicate with the device while the UPnP port is used when streaming media.
 * `Prefer external EPG over OTA`: If a specific channel has guide data both from the VBox itself and from the external XMLTV file, this setting controls which guide data is used. Note that the external data is always used if the VBox doesn't provide any guide data for a specific channel.
 * `Timeshift buffer path`: The path where the timeshift buffer files should be stored when timeshifting is enabled. Make sure you have a reasonable amount of disk space available since the buffer will grow indefinitely until you stop watching or switch channels!