Added %filename%, %path%, %ext%, %root_path% variables, apply button, example field, etc.

[Universal-Invariant]

Added a textbox that can view result as an example. Added the ability to remove quotes from variables such as %path%. Added apply button that does not close the window but applies changes.

I haven't programming in VB in a long time and the editor threw me off a little so I hacked things together to get the layout right so you might want to take a look at that to make sure it's good enough.

[stax76]

Today, I announced my retirement from maintaining this project. I'm sorry not being able trying to merge and release this PR.

The announcement.