irc: add value "353" in option irc.look.display_join_message

So now the values mean:
- 353: names on channel
- 366: names count (before this commit it meant 353 + 366)
core: fix typo in NEWS
core: fix typos in translations and docs
doc: replace weeget.py by script plugin in plugin API reference
relay: send backlog for irc private buffers
irc: clear the gnutls session in all cases after SSL connection error
core: fix crash when creating two bars with same name but different case (bug #41418)
core: fix compilation on Android (replace calls to rindex by strrchr) (bug #41420, patch #8301)
core: update German translations
doc: add French developer's guide
Version 0.4.3-rc2
core: update ChangeLog
doc: minor changes in developer's guide
core: fix compilation on Android (replace include of sys/termios.h by termios.h) (bug #41434)
ruby: fix compilation warning
doc: add French version of relay protocol
core: use structure itself for sizeof in two malloc
doc: fix typos in French relay protocol
core: fix a French translation
alias: add default alias /beep => /print -stderr \a