Re-add 'Cowardice' and 'Aggressiveness' UCI options

I have lost my bet with Jean-Paul, so now I re-add
the two options...and I am glad of it :-)

No functional change.

polyglot.ini

@@ -24,6 +24,8 @@ Mobility (Endgame) = 100
 Passed Pawns (Middle Game) = 100
 Passed Pawns (Endgame) = 100
 Space = 100
+Aggressiveness = 100
+Cowardice = 100
 Min Split Depth = 4
 Max Threads per Split Point = 5
 Threads = 1