added: TimeZone struct (core)

this class has information about a time zone (utf offset, daylight saving time)
       and methods for converting between UTC and local time
       structs User and Config has a TimeZone object
       System::ToLocal() and System::ToUTC() uses it for converting
       (depending whether a user is logged or not)


git-svn-id: svn://ttmath.org/publicrep/winix/trunk@842 e52654a7-88a9-db11-a3e9-0013d4bc506e

core/config.cpp

@@ -210,9 +210,6 @@ void Config::AssignValues(bool stdout_is_closed)
 	NoLastSlash(plugins_dir);
 	ListText(L"plugins", plugin_file);
 
-	time_zone_offset       = Int(L"time_zone_offset", 0);
-	time_zone_offset_guest = Int(L"time_zone_offset_guest", 0);
-
 	utf8 = Bool(L"utf8", true);
 	symlinks_follow_max = Size(L"symlinks_follow_max", 20);
 
@@ -238,6 +235,9 @@ void Config::AssignValues(bool stdout_is_closed)
 
 	account_need_email_verification     = Bool(L"account_need_email_verification", true);
 	reset_password_code_expiration_time = Long(L"reset_password_code_expiration_time", 86400);
+
+	time_zone.SetTz(space);
+
 }