Set up automatic building for offline version

[mariopesch]

We should use Travis and AppVeyor for automatically building offline Versions for Windows, Linux and Mac OS.

[mpfeil]

@mariopesch checkout branch appveyor. The appveyor config file creates an automatic build nad releases it on github.

We should discuss version numbers and names and if Windows build is enough for the beginning.

[mariopesch]

Perfect @mpfeil, thank you! I think Windows is enough for an offline version as nearly all schools use windows computers. We can build the Mac OS and Linux version manually. Can anyone with a Windows Computer confirm that the offline Version is working? maybe @buchwaldchassee @synolus-david

[mpfeil]

With appveyor we can also build the Linux version.

[synolus-david]

No issues on Windows 10 as far as I can evaluate that ;-)