Fix hang in mini-Expect scripts, use Go modules

Fix hang in mini-Expect (issue #13), use Go Modules.

Minor fixes

Small updates to eliminate a potential data race and remove references to terminals after D210.

A binary (zip file) is included for Windows 64 systems (tested on Windows 10).

Fix ErEOL bug

Two fixes: Erase EOL was not working properly, and there was a long-standing typo in one of the self-test strings.

Better Terminal History

The main visible change in this release is a more intuitive terminal history accessed via a scrollbar.

Various bugs are also addressed, including #9 and #10. Telnet reconnection should now work without restarting the application.

XMODEM Support

The following changes have been made:

• Added full function key template
• XMODEM-CRC File transfer (receive seems good, transmit needs more testing)
• Fix to crash when serial port closed
• Minor performance improvements
• Console messages are now more consistent

Add Icon and Copy/Paste

There is now an icon in the package which can be used by desktop managers for the app.

Pasting from the clipboard is now supported from the Edit menu.

Copying to the clipboard is achieved by simply swiping over the selection with the mouse (it is temporarily underlined to highlight the selection).

First release with new serial package and BREAK handling

A long-overdue release as I now have third-party verification that it works fine over serial lines to a real MV-class machine.