Bump version to 1.0.11 and update CHANGES.md

CHANGES.md

-1.0.10 (2015-04-16)
+1.0.11 (2016-11-27)
+-------------------
+* Update to libsodium 1.0.11
+
+1.0.10 (2016-04-16)
 -------------------
 * Update to libsodium 1.0.10
 * Windows support fixups, take 2 (hopefully actually working)
 
-1.0.9 (2015-04-02)
+1.0.9 (2016-04-02)
 ------------------
 * Update to libsodium 1.0.9
 * Windows support fixups

lib/rbnacl/libsodium/version.rb

 module RbNaCl
   module Libsodium
-    VERSION = '1.0.10'
+    VERSION = '1.0.11'
   end
 end

libsodium @ 2f4f718c

-Subproject commit fce6852d64339efa33c0ee4130b3107b888d6067
+Subproject commit 2f4f718cd94adab547c210a78050762cf667dfca