[S32/IO] spurt now overwrites by default

It fails on existing files only if you pass it the new `:new` option.

S32-setting-library/IO.pod

@@ -22,8 +22,8 @@ DRAFT: Synopsis 32: Setting Library - IO
 
     Created: 19 Feb 2009 extracted from S29-functions.pod; added stuff from S16-IO later
 
-    Last Modified: 24 June 2012
-    Version: 14
+    Last Modified: 6 July 2012
+    Version: 15
 
 The document is a draft.
 
@@ -954,35 +954,42 @@ The routine will C<fail> if the file does not exist, or is a directory.
         Str   $contents,
         Str  :$enc = $?ENC,
         Bool :append = False,
+        Bool :new = False,
     )
     multi method spurt ($handle:
         Buf   $contents,
         Bool :append = False,
+        Bool :new = False,
     )
     multi spurt (IO $fh,
         Str   $contents,
         Str  :$enc = $?ENC,
         Bool :append = False,
+        Bool :new = False,
     )
     multi spurt (IO $fh,
         Buf   $contents,
         Bool :append = False,
+        Bool :new = False,
     )
     multi spurt (Str $filename,
         Str   $contents,
         Str  :$enc = $?ENC,
         Bool :append = False,
+        Bool :new = False,
     )
     multi spurt (Str $filename,
         Buf   $contents,
         Bool :append = False,
+        Bool :new = False,
     )
 
 Opens the file for writing, dumps the contents, and closes the file.
 
-This routine will C<fail> if the file exists, unless the C<:append> flag is
-set, in which case it will instead add the given contents at the end of the
-file.
+If the C<:new> flag is set and the file already exists before opening, this
+routine will C<fail>.  With an unset C<:new> flag, the file will instead be
+silently overwritten, unless the C<:append> flag is set, in which case the
+routine will instead add the given contents at the end of the file.
 
 The routine will also C<fail> with the corresponding exception if there was any
 other error in opening, writing, or closing.