#384 Add mouse button function display

[Anonymous]

My post from the xastir mailing list:

I just drew some things with xfig and remembered that
it shows the current function of each mouse button on
the menu bar. Would implementing something similar on
Xastir be difficult? The display could be on the right
side of the arrow buttons at the top of the window.
This way even those of us who never bother to read the
docs could easily see what each button does in each
mode. Then there are the more complex functions like
press-and-hold-the-button-and-move-the-mouse for
zooming to specific area, I don't know how to show
these to the user understandably in a short space.

Tapio, OH2KKU (@iki.fi)