Support for WAR file processing

[radomirml]

Submitting this PR as recently suggested by @cmorty .

I guess WAR specific instructions from the README.md should be moved to a more appropriate location before merging.

[Lonzak]

I would be interested in this, too.
@wvengen can you accept this PR? What is the problem?

[wvengen]

Thanks for the changes. Ideally this would have been rebased, and not include the fork-specific README changes, to be a clean PR.
@cmorty do you think the code changes are fine?
I can try to find some time to pick the relevant changes and merge them.

[Lonzak]

I can try to find some time to pick the relevant changes and merge them.

That would be highly appreciated. Thanks!

[lasselindqvist]

I would like to merge this, but this needs to be completely redone on top of the changed code. I cannot easily resolve the conflicts myself.