Bugfixes

This fixes #8540 (hopefully) - there is one iterator increment to much.

Fixes #8469 - language names taken from http://msdn.microsoft.com/en-us/goglobal/bb896001.aspx

Fixes #8307 - prevent accessing an empty dreams vector.

Fixes #8416 - remove unnecessary null pointer checks

About 4f40f7f: Compare with game::update_map - the code in shift_monsters assumes that levx and levy already point to the *new* coordinates. When debug teleporting only a single overmap tile away, the monster positions have been screwed because of this.