icon mouseovers should mention keyboard shortcuts

[jidanni]

In the manual we read

Pan
...
This mode can also be entered by the keyboard shortcut Ctrl+Shift+P or now more simply just p

OK, but the mouseover for the Pan icon should also mention "(p,Ctrl+Shift+P)" else users could go through life only finding out years later how much easier life could have been. Currently it only mentions "Pan Tool".

Same for the other icons.

Yes, even if the whole list is in .config/viking/keys.rc .