Feel like we've got a few too many moving parts at the moment,
so explicitly set versions of our dependencies.

Also took the opportunity to upgrade a couple of things.

Change-Id: I1af4dbfbbd149e5a4c64e83f66de015affcf4032
Reviewed-on: http://gerrit.dmdirc.com/4001
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>

Change-Id: I76d9cabb6a550116cee644b0d92cbf3ef7adfd6a
Reviewed-on: http://gerrit.dmdirc.com/3851
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>