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

* 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>

Change-Id: I8608be6d035c9d7deeca526047f3f60c0f0f7777
Reviewed-on: http://gerrit.dmdirc.com/3051
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>

Change-Id: Ib0dcdb36dda3711654878782799a4a48e8195c94
Reviewed-on: http://gerrit.dmdirc.com/2802
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>

Depends-On: I34d7849a75cd4c7a91e04a9dad6f8073aa5a8f61
Change-Id: I65d96f91e1eb5ed7afb43dd41cd00531d809878d
Reviewed-on: http://gerrit.dmdirc.com/2736
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>