Check for latest version

[The-Gig]

The idea is simple: adding a button to allow players to see if a new version of MonsterBrowser has been released.
I suppose the button could just check for an URL pointing to a text file (hosted somewhere in this github?) where you would just write the number of the latest official release, and show that string into a dialog window. So people could easily know that there is a new version available, and the window could contain a link to https://github.com/torhus/monster-browser/releases.

I don't know, maybe it may be part of an "About/Info" menu/screen, where you could also place links to https://sites.google.com/site/monsterbrowser, https://github.com/torhus/monster-browser, and to the included readme.txt and changelog.txt?

[The-Gig]

This led to the opening of issue #32