Version 30

- |NRL| throws erros, when used without having first narrowed a region - |NRV!| not allowed (reported by ping, thanks!)- when using single window narrowing, :w would jump back to the original window. Only do this, when 'hidden' is not set (reported by ping, thanks!)- when narrowing a region, the last visual selected region wasn't correctly restored (reported by ping, thanks!)- some code cleanup- recursive narrowing was broken, fix it (reported by ping, thanks!)(automatically uploaded)