* v1.0d15.5 -  1/17/92 - Modified the underscore character in the HexEdit font
*                        so that it's 1 pixel higher. This fixes the wacky
*                        behaviour discovered in d15.4, and it doesn't really
*                        cause any serious problems. Only the truly picky will
*                        notice (those like myself :-).
*                      - Modified the delete/clear pro-processing to only pass
*                        the two chars when, for clear, selectionStart = 1, and
*                        for delete, selectionStart = 0.
*                      - BuildThisLine now can pass on partially blank lines
*                        (draws only the offset), or fully blank lines (entire
*                        buffer of spaces). This corrects the problem where the
*                        last byte on a line was deleted, but the char still
*                        remained on the screen. This also allows us to have a
*                        line with only an offset drawn (the record contains an
*                        integral multiple of 16 bytes). In this case, the first
*                        location on a line is for the 'new' byte.
*                      - For controls that currently have no code associated
*                        with them in the Script/Hex options dialog, I've set
*                        the upper byte of their flags field (in hex3.rez) to
*                        $FF. This sets their initial state to inactive hilight.
*                      - Added a menu to HexEdit. It currently has a single
*                        item, 'Insertion Mode'. It also does absolutely diddly
*                        squat if selected.
*                      - Fixed the cursor update problem when in insertion mode
*                        with the ASCII side as primary. I added 16 bytes to the
*                        dual-use IncrementTable in FastDrawHilight. The table
*                        was originally intended to be used with hex side only,
*                        and as such didn't have the proper mask index vals for
*                        the ASCII side.
*                   
* v1.0d15.6 -  1/18/92 - Modified the "only whitespace update" checking code in
*                        HEUpdateInternal. This fixes a problem when the record
*                        is an integral multiple of 16 bytes and the last line
*                        is the only line to be updated. In the old case, it
*                        would be ignored.
*                      - Modified HEScrollInternal to sense when an update after
*                        a scroll would use the direct screen drawing code. In
*                        that case, it does not do a ScrollRect or EraseRect.
*                      - Broke UpdateForEdit redraw into two distinct updates.
*                        We now update the hex/ascii data separately from the
*                        vert scroll bar. This allows us to get the benefits
*                        from the direct to screen code, and we can do some
*                        tweaks so the scroll bar arrows don't flash.
