Quite a while back I got that to work with JailCoder, but that was an older version of XCode and OS X (though also iOS 5 on an iPad 2). I just asked google real quick and it seems to be broken for recent versions of iOS, but kind of works for Xcode 6 (see the most recent post on their facebook page).
It might be worth a try or at least as a starting point for further investigation ;-).
Thanks a lot for your feedback. I will give JailCoder a try.
Just an update from my research :
As i understand, it is possible to build for iOS 5.1. The project should be configured to use iOS 8.1 SDK but it is possible to specify to deploy for iOS 5.1. I can’t test if it works as i can’t be able to send the app to the device yet.
Now the problem is sending the app to the device without Apple Developper Program.
seems promising but still can’t deploy the app as Xcode keeps complaining about Apple Developper Program, even if i disabled it in the .plist file.
Concerning the code signing : i tried a self signing code as described in the link above. still asking for an Apple Developper Program. Then i tested with configuring Xcode not tu sign code, app is building but not deployed.
Then i tried to grab the built app and send it to the device manually (in the device root Application directory, i don’t know if this is the correct path). The app appears in the device but it won’t launch.