An updated subclassing tool

[hutch--]

This tool was originally written back around the year 2000, was "warmed over" about 2015 and has just been turned into the year 2022 model. Minor internal code changes, cleaned up and modernised the interface and tidied up the code generation to better fit the current PB compilers.

There are two files in the zip file, "subclass.exe" and the temporary output viewer, "tview.exe" which must be in the same directory as the subclass tool.

Subclassing is a technique to intercept the default message processing for a control. It is where you can modify or throw away messages of your choice then pass the messages back to the default handler. Incredibly useful technique that extends what you can do with most controls.