Input Processor / Object changes

I changed Player a bit so that I could work with it more easily. For
example, I added a maxStamina variable that never changes. I changed
stamina to be a double since regen is a double. When I'm adding regen
values to it, I don't want it to round off. I added in a baseSpeed
variable that never changes. This is so that I can simply multiply the
speed by 2 when the player is running and I don't have to do anything
past that. After they are done running, I can set the speed back to the
base speed. I added in an initialLocation so that if the player dies,
the game can restart exactly how it started. I also made the x and y
coordinates be doubles. This is because the speed is a double which
means that the location of the player is changing by a value that is not
a double. I still have a getLocation() method that returns the player's
top left corner location on screen. Lastly, I added in a getCenter()
method which returns the center point of the player. This would probably
be used by Vivek for the lighting effects. If anyone wants to know more
about the changes,  post an issue on the GitHub. If there are
suggestions for more things to add, things to delete, things to change,
or things to simplify, also just post an issue on the GitHub.

The InputProcessor handles keyboard input and does the player movement /
player collision checking. There are quite a few comments in it, but I'm
open to questions or suggestions.