Update Guave to v16

Change-Id: I69c3a04c92f002a39b470f6246ce14ca9b4b849b
Fixes-Issue: CLIENT-485
Reviewed-on: http://gerrit.dmdirc.com/3306
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>
Update submodules: plugins (new commits)

plugins:
    06371e9 Greg Holmes <greg@dmdirc.com>
            Remove Guava now its in the core

            Gerrit: http://gerrit.dmdirc.com/3305

Change-Id: Iddbfc5d39a019fbc98afad2ce2084371c8eff90d