Initial release of 'itemshop' and 'pointshop'
-- Suggestion: http://rathena.org/board/topic/84169-specialty-shops/
-- Credits: Aleos & Akinari for first diff file that I used to finish this and testing/debugging (well, I don't know the original ones, just tell us or just do pull request if you know the first creator.)
-- How to use?
---> -%TAB%itemshop%TAB%<NPC Name>%TAB%<sprite id>,<costitemid>,<itemid>:<price>{,<itemid>:<price>...}
---> -%TAB%pointshop%TAB%<NPC Name>%TAB%<sprite id>,<costvariable>,<itemid>:<price>{,<itemid>:<price>...}

Signed-off-by: Cahyadi Ramadhan Togihon <house.bad@gmail.com>