Count cache hits and misses, report them on SIGUSR2.
Count cache hits and misses, report them on SIGUSR2.

--HG--
branch : HEAD

jkerihuel/dovecot,dscho/dovecot,dscho/dovecot,jwm/dovecot-notmuch,jkerihuel/dovecot,jkerihuel/dovecot,jkerihuel/dovecot,dscho/dovecot,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jkerihuel/dovecot,dscho/dovecot,dscho/dovecot