* Improved performance when saving large history logs by rewriting text-retrival code with care to cut down the number of memory allocations, simplified things generally as well.

* Performance when working with 'unlimited' history logs (Settings > History > "Set Unlimited")
improved by mmap'ing the log files when many consecutive reads occur.

* Added support for exporting terminal history (aka. "scrollback") to web pages (HTML).
Select "Edit > Save History As..." and select "HTML" in the Filter dropdown.

The HTML is quite lengthy at the moment, will work on that in future.

Suggestions on other export formats that would be useful are welcome :)