core: remove obsolete/unneeded check of headers and functions in cmake and configure
scripts: do now allow empty script name in function "register"
core: fix typo in ChangeLog
core: display error number and string in some network errors

Error number and string is now displayed when an error is returned by one of
these functions: socket, setsockopt, fcntl, pipe, accept, bind, listen, mkfifo.
core: sync debian files with debian git repository
irc: add color in output of /names when result is on server buffer (channel not joined) (bug #38070)
doc: add command "/script" in scripting guide
doc: add example of callback in each language (scripting guide)
doc: use boxes/arrows chars for diagram in differences with C API (scripting guide)
doc: fix monospaced font used for literal and listing blocks in japanese
core: use default hash/comparison callback for keys of type integer/pointer/time in hashtable
core: use size of 32 for hashtables (instead of 4, 8 or 16)

A size of 32 will use a little more memory but will reduce collisions in key
hashs, and then length of linked lists inside hash structure (faster search in
hashtable).
core: fix hidden lines for messages without date when option weechat.history.max_buffer_lines_minutes is set (bug #38197)
core: add "/debug tags" in /help filter
irc: fix typo in comment
doc: fix typo in user's guide
core: fix detection of python on Ubuntu Raring
aspell: optimization on spellers to improve speed (save state by buffer), add info "aspell_dict", add completion "aspell_dicts"

Two hashtables have been added to store the spellers currently used (in all
buffers) and info for each buffer: array with pointers to spellers and state of
aspell for this buffer.
Therefore the spellers are not destroyed and created again on each buffer switch,
or each time screen is refreshed when window is split.
relay: add comments with example of messages in weechat protocol
relay: add return of a NULL pointer in command "test"