Merge remote-tracking branch 'origin/master' into v2
* origin/master:
nntp: allow and ignore empty commands
mbox: do not barf on queries which return no results
nntp: fix NEWNEWS command
searchview: fix non-numeric comparison
Allow specification of the number of search results to return
githttpbackend: avoid infinite loop on generic PSGI servers
http: fix modification of read-only value
extmsg: use news.gmane.org for Message-ID lookups
extmsg: rework partial MID matching to favor current inbox
Update the installation instructions with Fedora package names
nntp: do not drain rbuf if there is a command pending
nntp: improve fairness during XOVER and similar commands
searchidx: do not modify Xapian DB while iterating
Don't use LIMIT in UPDATE statements