Merge pull request #37 from ibara/master

More English localization cleanups.
Fix groups of 3 lines in English dialogs.
Fix switch in dungeon 3 (#36)
Merge pull request #38 from pdewacht/master

Fix for dungeon 3 boss key room
Fix nil destination in dungeon 3 (#36).
Fix Arbror root movement
Fix Master Arbror / Arbror root linkage
Fix Master Arbror immobilized root counter
Merge pull request #39 from pdewacht/master

Partially fix Arbror
Fix a missing parameter with the surprise wall dialog.
Fix a typo in French dialogs.
Fix all errors with destination being possibly nil.
Fix dungeon 3 miniboss.
Fix entity names in dungeon 3 to call set_entities_enabled() correctly.
Billy's cave: function billy_leave() referenced before definition
Fix bandit fight in smith's cave
attempt to index global 'lamp' (a nil value)

At this point in the game the lamp is no longer available. So `lamp:remove()`
fails because `lamp` is nil.
Merge pull request #40 from pdewacht/master

Today's fixes :)
Fix dungeon 3 Arbror boss (#41).
Fix segfault when Link is thrown into prison

`guard:stop_movement()` deletes the entity's movement, but
`guard:set_position()` (`NPC::notify_position_changed()` in the engine)
assumes it is non-nil when the current animation is "walking".

I don't know what the proper fix is, but simply delaying the stop_movement
seems to work.