Move strings in ultralcd.cpp into language.h.

Okay, this is the replacement merge request for (https://github.com/ErikZalm/Marlin/pull/749), so you can delete/close that one.

I have built this with all 9 current languages, with and without ULTRA_LCD, SDSUPPORT and ULTIPANEL defined (not individually, all or nothing).

I see there is a new request from Daniel (https://github.com/ErikZalm/Marlin/pull/760) pending. If you do his one first, I'll update my branch with the Aragonese block and update this ticket when it's ready - this one *will* conflict with 760 as it stands.