NNetSimu 4.1

Version 4.1 of NNetSimu was released on Jan 10 2022.

This version includes some bug fixes and small improvements
 * Extend IoLines with space bar
 * SelectionMenu
 * Detach synapse by moving away from main pipe
 * Selection handling simplified, now without SHIFT key
 * Link to documentation in help menu

Previous version: NNetSimu 4.0

Succeeding version: NNetSimu 4.2 (not yet released)