With this Patch it is not possible to delete the group "All Channels" under the Tv and Radio Groups.
And if you add a Group under Tv or Radio Channels an then click cancel the Group is not created anymore.
There is also a problem if you delete the "all channel group" and then make the epg mapping of all grouped channels. you will get wrong entries checked. i will provide a patch of this later.
I have added the Cancel while adding a group to SVN from your patch.
As chemelli already mentioned, the group is always recreated and perhaps you want to have it recreated automatically. Therefore this wasn't added to SVN aswell.
Maybe we can throw a question to the user if he wants to delete the "All channels group".
"restart the tvserver?" or if the user selected the all channels group the button gets a new label, "Recreate Group" ?