* switching from wrapping to non-wrapping mode triggers a recomputation of
the text rect
* non-wrapping mode now triggers updating of the data rect for the horizontal
scrollbar as needed, fixing #4705
* corrected a couple of width computations that confused bounds and text
rect width, leading to drawing artefacts at the end of a line
* unified computation of text rect width to always take all lines into
account (not just the first one)
* some cleanup
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33703 a95241bf-73f2-0310-859d-f6bbb57e9c96
Oliver Tappe
b18f133db3