All of my latest hell deaths code excluding my graphics code changes

The graphics code changes I've excluded (because they aren't ready to be used in *CorsixTH*) would fix the *on_ground* animation's "missing hats and white shoes" bug, by removing the need for the standard male *on_ground* animation to be used.

Changes I've made since Mark copied my old code into his repository:

**Code Style Changes:**
To make my code follow the Corsix code conventions and to make it more readable I've made these changes:
1. The variables in my Lua code no longer have CamelCase names instead they have lower case underscore seperated names.
2. I've split up long lines of code (>80 characters) into multiple lines, for example: by having function parameters be listed vertically instead of horizontally.
3. Horizontally listed parameters are now spaced like this:
(v_one, v_two, v_three)
4. I've replaced some tabs I found with spaces.
5. I've split single line IF & FOR statements into multiple line statements because this increases their glancing readability.

**Code Changes:**
1. The *"alt + s"* sound hotkey will now call *Audio:soundEffectsOn(state)*, turning lava hole sounds off and on accordingly.
2. *World:getHellDeathSpawnPoints()* now makes sure that the lava hole use tiles for the hell death spawn points being checked, won't be in rooms.
3 *World:getHellDeathSpawnPoints()*: I've replaced the stair case of IF statements that was in this function with one IF statement which has all the conditions from the previous IF statements in its  condition.
4. I've included my *idle_spawn* persistance fix in this commit despite having pushed it to the *CorsixTH* repository in its own pull request because hell deaths can't be persisted without it.
5. I've removed 3 unnecessary functions which were added by my old code:
     - *World:updateTypeAnimations()*
    - *World:initTypeAnimations()*
    - *World:doesEntityExsist()*
6. *World:setType()* is now as it was before it called *World:initTypeAnimations()*
7. *World:afterLoad()* no longer calls *World:updateTypeAnimations()* for old saved games.
8. *Patient:afterLoad()* is now responsible for giving patients from old saved games the new hell death animations.
9. The saved game version number is now 84 because 83 has been used by my Chewbacca death animation fix pull request.
10. I've replaced *utility:tables_length()* calls with calls for *utility:table_length()*