First AppImage for Imaginario

As a follow-up to my previous post, I've finally succeeded in building Imaginario as an AppImage package.

I've smoke tested the package in Ubuntu Xenial and Trusty, and while it appears to be working, I'd be happy if someone else could also download and test it in their machines and let me know how it goes. Just please keep in mind that this a very beta release and, while I'm not aware of any major bugs that could corrupt your photos, I wouldn't recommend you to import your photo archive into it, unless you backup it first.
Also, the application needs quite some more polishing before being ready to be publicly advertised to non developers (I'm also considering finding a new icon for it), so the next step after getting a nicely working AppImage will be cleaning up the user interface and make sure that all the (few) features work as advertised. And making a Windows version. And a MacOS one. Oh, I'd better stop thinking about it, or I'll start crying.