This patch changes how transformations are realized by adjusting the
computed size of the new domain after transformation. Previously, this
was computed with the lower left corner of the domain as the origin of
transformation, while now, the center of the domain is used as the
origin. Consequently, domains shrinks/grows around their center, which
results in a more stable output as transforms are animated.
A consequence of this change is that we can no longer scale odd sized
domains to even sized domains or vice versa, since it grows/shrinks by
the same amount on both sides. Supporting this case requires further
investigation and will probably require passing down information to the
realization functions themselves.
0a6b43c827