view: Anchor right/bottom edge only when resizing via top/left edge
Currently, we anchor the right/bottom edge of the view whenever the top/
left edge is moving (current.x/y != pending.x/y). Doing so doesn't make
much sense when the right/bottom edge is also moving. In that case it's
probably best to move the view (or at least its top/left corner)
directly to its final position.
The most noticeable effect of this change is with views that don't
accept their requested size exactly when tiled or maximized (examples:
havoc, xfce4-terminal). Previously, their right-bottom corner would be
aligned with the screen edge, leaving gaps on the left and top. Now the
top-left corner will be aligned and the gaps will be on the right and
bottom. This is still not ideal, but IMHO less surprising to the user.