Fix assorted PMD errors.

Change-Id: I9af7e36f2aeb10bd658c5825ad2f94161e0bb243
Reviewed-on: http://gerrit.dmdirc.com/3940
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager

Change-Id: Ia9bb44a6ac02aec3d5991a1d3a9a003a344b6947
Reviewed-on: http://gerrit.dmdirc.com/3919
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager

Change-Id: I11efabb2757d8e62127b6487cbeb62d240cbd891
Reviewed-on: http://gerrit.dmdirc.com/3874
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager

Change-Id: If1bc20d15561584c9296ad10f04957efb51c5966
Depends-On: I6ef45d10a4fe862854702eee671114ee09f01d4d
Reviewed-on: http://gerrit.dmdirc.com/3867
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>

* Move all plugins to their own top-level directories.
* Move resources out of source trees
* Add Gradle build scripts.
* Remove ivy and ant build scripts.

Change-Id: Ib69a48ef26800c174ccf51c84ff9d1f73529460f
Depends-On: I303b6b69518468f98d48d835b8f40135d9e4bcbf
Reviewed-on: http://gerrit.dmdirc.com/3850
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>