PEP 343 -- the with-statement.

This was started by Mike Bland and completed by Guido
(with help from Neal).

This still needs a __future__ statement added;
Thomas is working on Michael's patch for that aspect.

There's a small amount of code cleanup and refactoring
in ast.c, compile.c and ceval.c (I fixed the lltrace
behavior when EXT_POP is used -- however I had to make
lltrace a static global).

Tools/compiler/ast.txt

@@ -20,6 +20,7 @@ Break:
 Continue: 
 For: assign, list, body, else_&
 While: test, body, else_&
+With: expr, vars&, body
 If: tests!, else_&
 Exec: expr, locals&, globals&
 From: modname*, names*
@@ -42,7 +43,7 @@ AssAttr: expr, attrname*, flags*
 ListComp: expr, quals!
 ListCompFor: assign, list, ifs!
 ListCompIf: test
-GenExpr: code 
+GenExpr: code
 GenExprInner: expr, quals!
 GenExprFor: assign, iter, ifs!
 GenExprIf: test