PMD should disallow whitespace in name.

Change-Id: Iaae5269567a3f5a2c9608f6714c6e639e3a6b2f7
Fixes-Issue: CLIENT-468
Reviewed-on: http://gerrit.dmdirc.com/3299
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>