Additional trait for all leaders

[Sgtslick]

3rd traits - also slightly rebalanced original traits.

**tweaked again slightly**

attached here: http://forums.civfanatics.com/showpost.php?p=11610189&postcount=3051

Please give feedback before v24 release so to smooth over any bumps.
http://forums.civfanatics.com/showthread.php?t=458872&page=3