Improved query and form data encoding (based on a very early version of the general URI percent-encoding rules).

- now correct encoding of space by '%20' in path segment, and '+' in query parameters.
Unify and fixed query parameters handling for libcurl and net implementation.
Fixed file uploading (various issue in libcurl, and net implementation).
Fixed form multipart encoding by using correctly the boundary.
Updated autotest cases.
Code cleaning.

library/network/http_client/src/http_client_session.e

@@ -60,28 +60,10 @@ feature -- Access
 
 	url (a_path: READABLE_STRING_8; ctx: detachable HTTP_CLIENT_REQUEST_CONTEXT): STRING_8
 			-- Url computed from Current and `ctx' data.
-		local
-			s: STRING_8
-			url_encoder: URL_ENCODER
 		do
 			Result := base_url + a_path
 			if ctx /= Void then
-				create s.make_empty
-				create url_encoder
-				across
-					ctx.query_parameters as q
-				loop
-					if not s.is_empty then
-						s.append_character ('&')
-					end
-					s.append (url_encoder.encoded_string (q.key))
-					s.append_character ('=')
-					s.append (url_encoder.encoded_string (q.item))
-				end
-				if not s.is_empty then
-					Result.append_character ('?')
-					Result.append (s)
-				end
+				ctx.append_query_parameters_to_url (Result)
 			end
 		end
 
@@ -420,7 +402,7 @@ feature -- Element change
 		end
 
 note
-	copyright: "2011-2016, Jocelyn Fiat, Javier Velilla, Eiffel Software and others"
+	copyright: "2011-2017, Jocelyn Fiat, Javier Velilla, Eiffel Software and others"
 	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
 	source: "[
 			Eiffel Software