Fix bug #1517990: IDLE keybindings on OSX

This adds a new key definition for OSX, which is slightly different from the
classic mac definition.

Also add NEWS item for a couple of bugfixes I added recently.
diff --git a/Mac/IDLE/config-main.def b/Mac/IDLE/config-main.def
index 1cdc0c5..4691a85 100644
--- a/Mac/IDLE/config-main.def
+++ b/Mac/IDLE/config-main.def
@@ -71,7 +71,7 @@
 
 [Keys]
 default= 1
-name= IDLE Classic Mac
+name= IDLE Classic OSX
 
 [History]
 cyclic=1