Update core to 2.263.3, args4j to 2.33

[zbynek]

... and change update the mock code to avoid some exceptions

[MarkEWaite]

I'm not sure why the PR build on ci.jenkins.io runs out of memory and spends 10 hours running, while the master branch completes in 30 minutes or less. Any insights to offer?

[zbynek]

So the main method checks for Exceptions with a comment that they have to be explicitly caught and program exited, otherwise the job keeps hanging. I guess if it encounters an Error instead (such as out of memory) it's not caught and it keeps hanging (maybe because of the memory monitoring thread that runs in parallel?).

I guess the next step is to try it locally with more plugins than the default ~50 and see if I can reproduce the out of memory.

[zbynek]

It turns out that this mock

 when(mockJenkins.getRootDir()).thenReturn(new File(System.getProperty("java.io.tmpdir")));

was the cause of builds running for hours and running out of memory. I originally added it to avoid some warnings in the log, but those are not critical.

[MarkEWaite]

Looks great to me. Thanks for making the change!

[MarkEWaite]

Merging since @kwhetstone had approved the changes previously.