fixed some issues with transforming objects.
fixed:
removed some 'magic munbers'
x and y values are now calculated correctly (integer rounding error)
scale is now calculated between 0.5 and 1 initially to reduce complexity
objects are now specified as being square, with their size given as a
proportion of the walls 100x100 area (eg so size of 20 means relative to
the 100x100 wall, the object will take up 20x20 space)