Move deprecation code in its own file (the code was getting big and not very interesting)

Move deprecation code in its own file (the code was getting big and not very interesting)

Some books are not in the eidetic memory so we can't access them thanks to ESO API.
So, in order to still be able to read them, I have added the possibility for some books to still hold all the necessary data to be able to display them. The text won't have the right language if the player changed his language since the day he saw the book but it is better than not beeing able to read them.