Always use eth0 for xbmc

[mk01]

@Roy Terhaar

this is for sure XBMCs internal "intelligence" ... (and even probably useful on stupid systems).
I see few options how to avoid that:
- patch the code, should not be that difficult to find the relevant line of code and disable the logic
- try reverse order of activating the interfaces - could be that the logic of XBMC is the easiest one - THE LAST activated interface is considered the correct/actual ... that means put eth0 into manual, let RPI + XBMC boot with wlan0, activate eth0 only after manually. maybe I'm right and you have solution
- use OWNER iptable matching module.

linux's network stack allows you to use so called SOURCE routing, that means routing traffic based on SOURCE conditions, not destination. that is easy to setup, but by default designed to work with IPs (from which the pkts are originating). so you will use OWNER matching module which allows you TAG pakets based on process name, uid(owner) etc.
so the point would be create match target for uid xbian (or even PID of running XBMC), mark it and route with source routing conditions via eth0.

it should be like 2-3 lines of commands, google is your friend.

decide, check the 2), tell back. if you would consider the 3) too complicated, ask again - as last resort I can open the man pages and tell you the commands.