core: add functions to manage array lists
core: add extra check on arraylist pointer in arraylist functions
core: reset data contents in function arraylist_clear if size_alloc_min > 0
core: add comment about argument "index" of function arraylist_search
tests: add tests of arraylist functions
core: optimize completion by using arraylists

With arraylist (vs weelist), the completion is about 50x faster.
It is visible on "/help [+tab]".
core: use a sorted arraylist for partial completions

With a sorted list, the partial completion is about 50x faster
(like other completions).
Merge pull request #222 from l/translation_ja

core: update Japanese translations
Merge branch 'arraylist'
doc: add file "wee-arraylist.c" in developer's guide
doc: update auto-generated files with hdata
core: update ChangeLog (add arraylists)
relay: add host in sender for IRC backlog PRIVMSG messages sent to clients
relay: use comma separator in option relay.irc.backlog_tags, check the value of option when it is changed with /set
irc: fix completion of commands /msg, /notice and /query
irc: add tag "nick_xxx" in invite messages
core: update ChangeLog
core: add contributor in AUTHORS.asciidoc
core: fix search/insert of elements in sorted arraylist with duplicates

The pointer and index returned is now the first element found with the value
(with the lower index if there are many elements with same value).
And the index for insert is the last element with same value + 1
(the higher index + 1).
core: add a .mailmap file

This file is used for example by command "git shortlog", to prevent duplicate
committers.