Reenabled a check which prevented the null hotkey from being reassigned.
Default bindings for the title screen hotkeys.
Update of the wose shaman unit image.
Changed the scope of some hotkey actions.

"Change Language" belongs into main_menu scope because it only works
there.
The Null hotkey has no scope instead of general.
Store some new and old unit images.
Fixed a character speaking after the unit died.
Replaced outdated images for the orcish shaman units.