Support scanning multiple applications/servers in one run

Affected parts: Configuration, Rules Executor, Reporting.

We could possibly do it quickly as a link to an independent report.
But maybe we should rather identify what can be reused and cross-linked between apps?

Jess:
Yes, the task is to just treat them as separate apps (for the most part... they could be part of a single run of windup). Additional rules that take advantage of links between applications could be added later on.

Right now, we don't even have rules that link between submodules within a single application, so I am not sure why this would be a blocker for multiple application support?