Changes since the last release:
- fixed read-only disk error with Pro-Dos v2 (#64)
- fixed failure to recognise inserted tape images.
- fixed missing icon end marker that risked crash under Win32.
- changed Comet symbol export to always scrape from memory (#63)
- changed symbol export to save use local line endings (#63)
- changed to use MSVC runtime DLLs instead of static linking.