Remove obsolete gameover.lua
Create player die function

Make sure that we close the inventory and other dialogs/prompts on player death.
Remove dialogs and prompts on player death

This should never, ever happen, but it's good to be safe.
Remove the last remains of smart spawntype
Don't interpret any keypresses if player is dead
Merge pull request #2244 from niamu/player_death

Player death fixes
Merge pull request #2245 from niamu/remove_smart_spawn

Remove the last remains of smart spawntype