This update adds support for dovecot 2.4, allows to limit the amount
of threads via the maxthreads option and fixes several bugs.
For 2.3, e. g. optionally use:
plugin {
fts = xapian fts_xapian = lowmemory=500 maxthreads=4 partial=3 verbose=0 fts_autoindex = yes fts_enforced = yes <...>
}