Update submodules: plugins (new commits), util (new commits)

plugins:
    0fe6bea Greg Holmes <greg@dmdirc.com>
            Fix changes to StreamReader/StreamUtils.

            Depends-On: Ia24b29f2fcd414d7b27bad52cc6fad6312179de5
            Gerrit: http://gerrit.dmdirc.com/4068

util:
    57bcea0 Greg Holmes <greg@dmdirc.com>
            Hide StreamReader behind StreamUtils.

            Gerrit: http://gerrit.dmdirc.com/4067

Change-Id: Id172b47187f5b2838e6c1cdc0dcca297cbc06901