[Linux] Add an option to close the client instead of minimizing to tray

[noodlejetski]

Clicking on the "close" button in the top right corner of the client doesn't completely close the client (as one would expect from the button), only minimizes it to tray. I don't want or need the client to constantly run in the background, and when I press the close button, I actually want it to close completely.

Before the recent Beta refresh, I could right click the taskbar icon and shut the client down completely that way, but right now it only minimizes the client to the tray icon, as well. The only way to completely close the client is to do that by right clicking the tray icon.

Consider adding an option to close the client completely with a single click of a button instead of making a user jump through these little hoops.

[stoechko]

I hardly approve this! We should have an option to choose if it minimizes to tray or closes.
Not just linux, any platform.