Update chat/weechat to 0.4.3

Version 0.4.3:
- new command /print
- logical and/or for tags in /filter and hook_print
- gaps in buffer numbers
- support of italic text
- new options to customize default text search in buffers
- use of IRC monitor command for /notify (if available on server)
- new IRC server option "ssl_fingerprint"
- new option to smart-filter IRC mode messages
- new option for default IRC ban mask
- support of IPv6 for DCC chat/file
- auto check CRC32 of files received with DCC
- many bugs fixed.

Version 0.4.2:
- rename binary from "weechat-curses" to "weechat" (with symbolic link "weechat-curses" for compatibility)
- add secured data (encryption of passwords or private data), new command /secure, new file sec.conf
- search of regular expression in buffer with text emphasis, in prefixes, messages or both
- add option "scroll_beyond_end" for command /window
- add optional buffer context in bar items (for example to display bitlbee nicklist in a root bar)
- new options weechat.look.hotlist_{prefix|suffix}
- new option weechat.look.key_bind_safe to prevent any key binding error from user
- new option weechat.network.proxy_curl to use a proxy when downloading URLs with curl
- display day change message dynamically
- support of wildcards in IRC commands (de)op/halfop/voice
- new option irc.look.notice_welcome_redirect to redirect channel welcome notices to the channel buffer
- new option irc.look.nick_color_hash: new hash algorithm to find nick colors (variant of djb2)
- add info about things defined by a script in the detailed view of script (/script show)
- support of "enchant" library in aspell plugin
- many bugs fixed.

(tonio)