Added visitor patterns to WSF_VALUE

Handling UTF-8 unencoding for WSF_VALUE ...
Added WSF_TABLE_VALUE to handle list[]=a&list[]=b ...

Library encoder: added UTF8 facilities

library/text/encoder/src/utf8_encoder.e

@@ -0,0 +1,70 @@
+note
+	description: "[
+				Summary description for {UTF8_ENCODER}.
+				
+				see: http://en.wikipedia.org/wiki/UTF-8
+		]"
+	legal: "See notice at end of class."
+	status: "See notice at end of class."
+	date: "$Date$"
+	revision: "$Revision$"
+
+class
+	UTF8_ENCODER
+
+inherit
+	ENCODER [STRING_32, STRING_8]
+
+	UNICODE_CONVERSION
+		export
+			{NONE} all
+			{ANY} is_valid_utf8
+		undefine
+			is_little_endian
+		end
+
+	PLATFORM
+		export
+			{NONE} all
+		end
+
+feature -- Access
+
+	name: READABLE_STRING_8
+		do
+			create {IMMUTABLE_STRING_8} Result.make_from_string ("UTF8-encoded")
+		end
+
+feature -- Status report
+
+	has_error: BOOLEAN
+
+feature -- Encoder
+
+	encoded_string (s: STRING_32): STRING_8
+			-- UTF8-encoded value of `s'.
+		do
+			Result := utf32_to_utf8 (s)
+			has_error := not last_conversion_successful
+		end
+
+feature -- Decoder
+
+	decoded_string (v: STRING_8): STRING_32
+			-- The UTF8-encoded equivalent of the given string
+		do
+			Result := utf8_to_utf32 (v)
+			has_error := not last_conversion_successful
+		end
+
+note
+	copyright: "2011-2011, Eiffel Software and others"
+	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
+	source: "[
+			Eiffel Software
+			5949 Hollister Ave., Goleta, CA 93117 USA
+			Telephone 805-685-1006, Fax 805-685-6869
+			Website http://www.eiffel.com
+			Customer support http://support.eiffel.com
+		]"
+end