"Need" Tasks for GearShift Beta

Update from Katherine:

So far, I have taken care of three different "Need" Tasks. They are the
"Max Gears on the Playing Field", "Lose Condition - Gears Removed", and
"Game Flow - Buttons".

In addition to the above, I also added "Gears Used" and "Gears
Destroyed" as available caps, in addition to the existing "Gears Placed"
and "Gears Removed" caps that are found on the Gear Counter. From
yesterday's work, there is also an available cap for the number of Gears
that spawn.

I made some bugfixes to the Null Gear so that they may only destroy
Gears that you originally placed. The only Gears under the player's
direct control are the prefab ones with the DragDropDestroy script.
Obstacle Gears, the Engine (Start) Gear, the End (Valve) Gear, and Layer
Spanning Gears will not be destroyed by the effects of the Null Gear.

Also, I simplified the Rusted Gear by removing the randomness of its
breaking and changing it to a fixed lifespan. Furthermore, Rusted Gears
no longer "wither away", but instead deteriorate only when they are
rotating. This means you won't be screwed if the Toolbox randomly spawns
with tons of Rusted Gears because you can place several Rusted Gears in
a chain without them falling apart.

To manage the conditions better, I created a separate script called
"ConditionalController" that keeps track of the Victory / Defeat Splash
Screens and sets them active. Other scripts will invoke the methods in
the Conditional Controller upon meeting the prerequisites to trigger
their respective events.