txt on CSD influence from killing barbarians

Thal: IMHO the added notification TXT_KEY_NOTIFICATION_MINOR_BARB_KILLED
belongs in the CEG module since it is only needed because CEG changes
the influence gained from killing barbarians. However there doesn't seem
to be a logical place to put it
Merge pull request #128 from skodkim/stable

txt on CSD influence from killing barbarians