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.

This saves getting the FS and suffering the barrage of warnings
related to auto-closeable resources.

This means each test doesn't have to set it up and tear it down
manually (although only one actually did bother to tear it down :)).

The "old" profiles were pre 0.6.3m1 - if anyone upgrades from that
long ago they'll just lose their profiles.

(aka the "IdentityTest")

Make it a lot less dumb, use a virtual FS so we can test reloading
and saving. Fix a bunch of bugs the tests highlighted.

Only things not really tested are the global config specific
behaviours.

Change-Id: I96448eb9c401ce864cd6f39fd95088a4a8a09727
Reviewed-on: http://gerrit.dmdirc.com/4015
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>