We put them below all other imports, checkstyle defaults to below
each group.
Also fix the formatting of the checkstyle config, replacing tabs
with spaces and fixing broken indentation/spacing.
Change-Id: I46f71e58f9ff4f8719ba59ff95d6415095058d21
Reviewed-on: http://gerrit.dmdirc.com/3121
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>