N O T E S   O N   V T E X T :

 * Made ComputeLine always read first character
 * Changed semantics of clicking at top, bottom

 * Extra colors for turns, dividers
 * Changed style names
 * Added clip mode
 * Assume NoHighlight is most common
 * Redraw is renamed Bad
 * Rearrange is renamed Move
 * Note don't use NoHighlight, OverlapStyle

 * RAISES clauses everywhere
 * If error, no guarantee on consistency
 * Shoudn't look inside views
 * Added VFont, MakeVFont
 * Removed MoveCaretFromIndex (use MoveCaret instead)
 * IsNil means an argument was NIL

 * Made Underline 2 pixels high

 * Eliminated Start

 * Removed vtext^.caret, interval^.hl, interval^.hr
 * Split Pounce
 * Added ConcurrentUpdate, LineIndex
 * Fixed ComputeLine

 * Implemented markers
 * BoxStyle implemented
 * Efficiency hacks

 * repaint less (rearrange doesn't)
 * SplitRegion, MergeRegion, Rearrange take a "scroll" argument
 * Redraw doesn't update
 * Redraw now obeys its rect arg

 * last line is not a priori turned

 * Removed charBox, charWidth from a VText record

 * Back to old cursor
 * Added VText.InsertSub
 * SplitRegion no longer does an update

 * Problem with Coral.DrawVText
 * VTPounce may do implicit update
 * Special hard-to-see caret
 * Macintosh-style selector for new-line

 * Made LinesBetween take a short-cut; changed its interface
 * Changed "text" component to "mtext"
 * Got rid of UpdateHighlights
 * Added concurrent updating
 * Added Quiesce, QuiesceRegion
 * Document new "update" philosophy

 * Eliminated anchorTop parameters to MergeRegion, Rearrange

 * Added "TempHead", "CopyHead" to pantheon
 * Removed start, newStart from exported list
 * Added Start function

 * Tabs, control characters work
 * Moved "intervals" from exported part
 * Switched caret to use xor (bad)
 * Eliminated MoveOrigin, unused anywhere

 * Changed most routines in EText.mod not to call Update
 * Fixed the scroll-bar operations to call Update, therefore
 * Fixed EText to compute desiredColumn only as needed

 * Removed usesTty, String, DefaultWindow, ReadyForCommand from VTextDisplay
 * Removed Restore from VTextDisplay
 * Fixed UpLines to work well with narrow (or zero-width) windows
 * Fixed VText to compute line width correctly (was off by leftMargin)
 * Reorganized VText to separate out VTextRegion, others
