- removed the help button, it won't be useful anymore
- relableded all buttons using minuscule (and not capital) lecters
- added the middle mouse button for some operations
In particular, the greatest change impacted the "toggle select" button. Pressing it with the left key will toggle selection, which means that files that were selected become unselected and vice-versa (it selects ALL files if none is selected, btw); the right key will drop selection (select none) and the middle button will let you select files using a pattern (this was, before, the function of the right button). But something changes also for the COPY button, which will work as usual when clicked with the left mouse button, but will "copy as" with the right button (copy and rename), and rename only with the middle button.
