Removed psyco from list of allowed imports - it's not safe after all.

Try/Except clauses are now allowed.

changelog

@@ -47,11 +47,12 @@ Version 1.5.0+svn:
    * Implemented a function which detects if a location is on the map border.
    * Implemented a function which gives the game's gold parameters.
    * Extended safe.py environment to expand AI's language capabilities; including:
-	collections, hotshot, psyco, Queue, sets, time, and the upcoming wail module
+	collections, hotshot, Queue, sets, time, and the upcoming wail module.
 	Use of chr, hash, lambda, ord, and super (new style classes) are now allowed
 	Control of safe_exec can now be toggled from the wesnoth binary (not implemented)
    * Added new advanced option, "Only Run Safe Python AIs". When disabled, the safe_exec
 	environment is disabled for all running AIs. Use caution when disabling this option!
+   * Try/Except clauses are now allowed.
  * terrains:
    * Fixed city village not being alias of the village terrain type; this was
      causing a duplicate "Village" terrain being displayed in the defense ratios

data/ais/safe.py

@@ -37,7 +37,8 @@ _NODE_CLASS_OK = [
     'LeftShift', 'List', 'ListComp', 'ListCompFor', 'ListCompIf', 'Mod',
     'Module', 'Mul', 'Name', 'Node', 'Not', 'Or', 'Pass', 'Power',
     'Print', 'Printnl', 'Return', 'RightShift', 'Slice', 'Sliceobj',
-    'Stmt', 'Sub', 'Subscript', 'Tuple', 'UnaryAdd', 'UnarySub', 'While',
+    'Stmt', 'Sub', 'Subscript', 'TryExcept', 'Tuple', 'UnaryAdd',
+    'UnarySub', 'While',
     ]
 _NODE_ATTR_OK = []
 _STR_OK = ['__init__']