Corrected a lot of code

I made corrections on Node, PathFinderController, and Searchingstate.
Missing parentheses on method calls, missing brackets, type errors, and
more.  I also added two empty objects to hold PathfinderController and
Node but it would not let me move the scripts onto them because they
won't compile yet.  I added tags to those empty game objects.
(PathFinder and NodeHolder)  Feel free to change that stuff.  Also take
a look at SearchingState. There is a bool variable defined for your
while loop that is not being used.