New content-aware resize tool ("smart resize")

This one's a big one!  PhotoDemon now supports automated content-aware
resizing via the Image -> Smart Resize menu.  (Shrinking only at
present; enlarging is coming soon!)

PhotoShop didn't gain such a feature until CS4, so this is cutting-edge
stuff.  Even GIMP has yet to implement this natively (though it can be
downloaded as a separate "liquid rescale" plugin).

Mine is an all-original, from-scratch implementation using the original
seam carving paper as a guide.  Performance isn't great (especially on
very large images) but I am actively investigating ways to improve it...
though references are hard to come by given the novelty of the approach.
The huge number of array accesses required doesn't bode particularly
well for VB6, but I'll keep researching.

(Hopefully users feel that a slow cutting-edge tool is better than no
cutting-edge tool at all.  :)

As noted above, image enlarging is a separate beast and I have yet to
implement it.  Hope to have that solved within a week or two.
Update README with new features, 2014 copyright, etc

It makes me very happy to finally include mention of PD's new
color-managed workflow!