"Home" button to open Windows Explorer in QIRX' Data Directory

[softsyst]

QIRX stores all its data (no Registry entries!) in the following directory (documented on the website):
C:\Users\myUserName\AppData\Local\qirxX, the 'X' usually being a 3.

This is in line with the usual behavior in Windows. However, this directory name is not easily remembered.
Therefore, it has been suggested to add a "Home" button on the top bar of QIRX which opens this directory in the Windows Explorer. The names of the subdirectories should be self-explaining.

Remark: This feature has been suggested by Richard Strang of Audio & Design in the UK.

[softsyst]

V3.1.5 implements the suggestion.