Fixed, now we erase all of the old stuff

Verified fixed in 11.30.98 build of xpviewer, as checked on NT 4 SP3 & Win98. Specifically verified proper reflow resulted during: * Shrinking and expanding of window borders * Shrinking the window sufficiently to invoke horizontal & vertical scrollbars, and scrolling during the page reflow * Slowly resizing the window during the text animation. I was able to corrupt the text box on the page on NT by shrinking the window sufficiently to require a horizontal scroll bar, corrupting the left-hand portion of the text box (as it intersected the animated text) Furthermore, please note that clicking around the region directly below the text box reproducibly crashed NGLayout. I haven't written any of these side-issues as separate bugs; if anyone would like them written up, please drop me a note (or just go write them up. ;)