Updated copyright notices to include the year 2018.
global: Log internal storage error on failure
Updated copyright notices to include the year 2017.
global: freshen copyright git ls-files | xargs perl -p -i -e 's/(\d+)-201[0-5]/$1-2016/g;s/ (201[0-5]) Dovecot/ $1-2016 Dovecot/'
push-notification: Log about unexpectedly failing mailbox functions. Found by Coverity.
Added push-notification plugin