Don't ask Main for the config directory.
Remove getMain() from Main.
Everything that needs a main now either gets given it, or asks something else.
Unfortunately, a few more dependencies on the static IdentityManager.getIdentityManager()
were introduced, but they can be tackled separately.
Fix unit tests for the above.

Depends-On: I9e42ac7f74453b739209a681d0a31f50c1be2a04
Change-Id: Ib5a9fdea5a2e25d5471d0b849f4f65fa0286d1f8
Reviewed-on: http://gerrit.dmdirc.com/2521
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>