Update to 1.7

Changelog:
[[v1.7]]
== Version 1.7 (2017-01-15)

New features::

  * core: add option weechat.look.align_multiline_words (issue #411, issue #802)
  * core: add optional command prefix in completion templates "commands", "plugins_commands" and "weechat_commands"
  * core: add optional arguments in completion template, sent to the callback
  * core: add option "time" in command /debug
  * api: add info "uptime" (WeeChat uptime)
  * api: add info "pid" (WeeChat PID) (issue #850)
  * fifo: add file fifo.conf and option fifo.file.path to customize FIFO pipe path/filename (issue #850)
  * irc: add server option "usermode" (issue #377, issue #820)
  * irc: add tag "self_msg" on self messages (issue #840)

Improvements::

  * core, xfer: display more information on fork errors (issue #573)
  * core: add a slash before commands completed in arguments of /command, /debug time, /key bind, /key bindctxt, /mute, /repeat, /wait
  * core: add a warning in header of configuration files to not edit by hand (issue #851)
  * alias: add a slash before commands completed in arguments of /alias
  * exec: add option "-oc" in command /exec to execute commands in process output, don't execute commands by default with "-o" (issue #877)
  * irc: evaluate content of server option "ssl_fingerprint" (issue #858)
  * irc: change default value of option irc.network.lag_reconnect from 0 to 300 (issue #818)
  * trigger: do not hide email in command "/msg nickserv register password email" (issue #849)

Bug fixes::

  * core: fix deadlock when quitting after a signal SIGHUP/SIGQUIT/SIGTERM is received (issue #32)
  * core: fix display of empty lines in search mode (issue #829)
  * api: fix crash in function string_expand_home() when the HOME environment variable is not set (issue #827)
  * exec: fix memory leak in display of process output
  * irc: fix option "-temp" in command /server (issue #880)
  * irc: fix close of server channels which are waiting for the JOIN when the server buffer is closed (issue #873)
  * irc: fix buffer switching on manual join for forwarded channels (issue #876)
  * irc: add missing tags on CTCP message sent
  * lua: fix integers returned in Lua >= 5.3 (issue #834)
  * relay: make HTTP headers case-insensitive for WebSocket connections (issue #888)
  * relay: set status to "authentication failed" and close immediately connection in case of authentication failure in weechat and irc protocols (issue #825)
  * script: reload a script after upgrade only if it was loaded, set autoload only if the script was auto-loaded (issue #855)

Build::

  * core, irc, xfer: fix compilation on Mac OS X (add link with resolv) (issue #276)
  * core: add build of xz package with make dist (cmake)
  * tests: fix compilation of tests on FreeBSD 11.0

(ryoon)