Fix detection of text wrapping
Fix detection of text wrapping

My new test code assumes that the height of a layout will increase each time \n is appended. It
hung the app and I traced it down to this.

ruslansennov/playn,threerings/playn,threerings/playn,ruslansennov/playn,threerings/playn,ruslansennov/playn,threerings/playn