function declared as inline rather than static inline.

WrapLines called before ensuring a lin eis visible so doc<->visible mapping
correct.
When modification changes number of lines, NeedWrapping starts one line
before.
Horizontal scrolling disallowed even more when in wrap mode.

rather than a hardcoded list.

have long names.

word characters following an insertion made by auto-completion.
Bundled the changes made by an autocompletion into one undo action.

More changes from Neil to avoid problem introduced by above with overstrike
mode replacing one character with two.
Comments about Digital Mars ifdefs.

Rather than storing a needWrap flag, there is now a record of the last line
wrapped, so if a change requires some rewrapping then the wrapping is only
performed for the line of the change and subsequent lines.
If a change in styling spills off the end of a line, such as occurs by
starting a multiline comment, that style change may change the width of
subsequent text so rewrapping is performed.
When window resized, rewrap only done when width changed as resize may be
only vertical.