Added Kevlin Henney from received permission.

[SVN r25143]

more/blanket-permission.txt

@@ -70,5 +70,7 @@ Dan Nuffer (dan -at- nuffer.name)
 Nicolai M Josuttis (solutions -at- josuttis.com) (See Boost list message of Mon, 30 Aug 2004 10:52:00 +0100)
 Christain Engstrom (christian.engstrom -at- glindra.org) (See Boost list message of Mon, 30 Aug 2004 14:31:49 +0200)
 Housemarque Oy (Ilari Kuittinen ilari.kuittinen -at- housemarque.fi)
+Kevlin Henney (kevlin -at- curbralan.com) (See Boost list message of Wed, 15 Sep 2004 18:15:17 +0200)
+