Request: Current folder url in title bar

[MrFlamey]

First, I'd just like to say thank you for making XnView. It is an amazing piece of software and I'm so happy that it is actively maintained and there is a multi-platform version so I don't miss it when I'm using Linux.

I have a fairly small feature request. In XnView for Windows, the current folder is displayed in the title bar of the application. When you have multiple XnView windows open at once, this makes picking the correct one from the Windows task bar very easy. However, XnViewMP (I am using 0.56) shows just "XnView MP v0.56 beta - windows x64", whichs makes picking the right window much more difficult. Please could you make the window title naming the same or similar to how it was in XnView for Windows?

[xnview]

Issue 11