Stop swimming against the tide and accept what most of the rest of
the world does.
While it adds an annoying depth to the actual source code, it makes
the root directory nicer (no more 'test-res' dirs), means we don't
have to override the gradle config, and makes it nicer to work in
IDEA 2016.1.
Also test.
Change-Id: Iea8cfe088b98782d7e7ccbdb3d862ab47dbe6273
Reviewed-on: http://gerrit.dmdirc.com/3955
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>