Friday Updates: Tracking Points

vis_control.fig: modified fig file to include velocity control among
minor adjustments.
vis_control.m: created and modified a few callbacks.
vis_gui_revised.m: added an option that would display differently if the
system was in different monitors.
caster_default_settings.mat: new rendered file from tests.
make_caster_default_settings.m: tried to dynamically generate settings
using functions from misc. This produces a graphics bug I cannot account
for at the moment.
Link.m: Updated fields to allow for TrackingPoint objects.
World: Updated rendering function to account for TrackingPoint Objects
TrackingPoint:.m: Creates a point relative to a figure that stores a
position relative to the World. This point is transformed in the same
way as link objects, and thus retains its relative position to the
object it is connected to.
Updated Readme

Changed README for the program to account for the current state of the
program.