* make CallTip and ToolTip sub-classes of a common abstract base class
* remove ListboxToolTip (unused and ugly)
* greatly increase test coverage
* tested on Windows, Linux and macOS
Fix-up class name duplication in PR #7807. Combined effect is that
module calltips and its class CallTips are now calltip and Calltip.
In module calltip_w class CallTip is now CalltipWindow.
Create a template for minimally testing a tkinter-using module by importing it and instantiating its class(es). Add a test file for all non-startup IDLE modules. Edit existing files and update coverage. This is part 1 of 3, covering the 21 autocomplete to help modules and touching 33 idlelib files.
Tal Einat
Terry Jan Reedy