Fixed Expansion Button and Placeholder bugs

Fixed the position of the Expand button, now located in the bottom right
of each workingAnimal object

Fixed the Placeholder remaining for a few seconds after it's object is
deleted (now it is deleted instantly)

Added animalType enumerated list which includes the allowed animal types
for more robust and obvious variable names.

Allowed the workingAnimal area to scroll when full of animals (may
implement workingAnimal limit later, if necessary.)

Added form Radio buttons inside of animals. The radio buttons are given
a unique id which includes the animal's ID number and the button's type
(the ID of the dog button for the first animal is 'dog0').  Added event
handler for when the radio buttons are changed. Added values to the
buttons which correspond to the animalType enumerated list.