Problem: Bulking message lines to write in a single API call is
complicated and still not correct w.r.t. overwriting
highlights.
Solution: Write each chunk pattern separately with it's highlight
such that it will be spliced correctly for message chunks
that contain a carriage return. Go with correctness over
performance until this proves to be too inefficient.
Also add an identifying name to the various extui buffers.
c973c7ae6f
