Add speech to entities

So that entities such as the player and sweaty reptile can speak
Used by calling talk(speech) on an entity
Test out speech

duck says "*quack lol*" when it quacks
Cancel old speech tasks if a new one is called

So that the speech isn't set to null from an old speech task that didn't
end before the new one was scheduled
Add SPEECH_PADDING

So that the text does not sit directly on top of the entity
Test speech on radio

Radio says "*beep*" when music is toggled
Add a float to determine how long speech should persist

SEC_PER_CHAR is how many seconds speech should last per character.
This is multiplied by the length of the speech string to determine how
many total seconds the speech should last.