caasdriver doesn't capture output of run test cases

[gradha]

At the moment caasdriver test case files can use the compile command to compile something. The output of the compilation is captured and thus can be tested for different behaviour in proc vs server mode. However, specifying compile --run seems to run the program but doesn't capture its output.

Can't think of a test where this may be necessary, but maybe this feature could be useful in the future, like verifying execution of a testcase matches the expected idetools output (see #477)?

[Araq]

So if you don't even know whether this would be a useful feature, why make it an issue? :P It's not like we aren't around on IRC to ask us ...

[gradha]

I could give excuses like the author of the tests not being available, logs sometimes being lost (or people not always paying attention to them), but the truth is github pays me per open issue and when I reach 50 I'll get a new unicorn.