luasocket escaping patch.

["Adam D. Moss" <adam@...>]

Hi!
This patch does two simple things:
1) url.escape() no longer escapes characters that don't have to
be escaped.  That makes its results more readable and thus
immensely more debuggable.
2) url.unescape()'s comments described url.escape().

--Adam
--
Adam D. Moss   . ,,^^   adam@gimp.org   http://www.foxbox.org/   co:3

Index: url.lua
===================================================================
--- url.lua	(revision 2999)
+++ url.lua	(working copy)
@@ -13,7 +13,7 @@
 --   escaped representation of string binary
 -----------------------------------------------------------------------------
 function escape(s)
-    return string.gsub(s, "(.)", function(c)
+   return string.gsub(s, "([^A-Za-z0-9_])", function(c)
         return string.format("%%%02x", string.byte(c))
     end)
 end
@@ -49,11 +49,11 @@
 end
 
 -----------------------------------------------------------------------------
--- Encodes a string into its escaped hexadecimal representation
+-- Decodes a string from its escaped hexadecimal representation
 -- Input 
---   s: binary string to be encoded
+--   s: encoded string to be decoded
 -- Returns
---   escaped representation of string binary
+--   unescaped binary string
 -----------------------------------------------------------------------------
 function unescape(s)
     return string.gsub(s, "%%(%x%x)", function(hex)