Bindings customization window

[nkh]

Let user change, or look at, the bindings rather than edit a file in te GUI. In the TUI simply open the file in the editor.

refactor the code that check binding override into a function so it can be used to check bindings when user changes them.

create, and document, the setup files automatically (the user setup files).

[nkh]

Write better documentation, user can read the manual and edit a text file.