* Bug Fixes:
-- Added itemstack check when init autotrader (bugreport:9077)
-- 'getitem' issue, gave unidentified item (bugreport:9075), follow up 62a2813
-- Invalid Def & Mdef reduction of SC_ARMORCHANGE & duration (NPC_STONESKIN & NPC_ANTIMAGIC), should be percentage (bugreport:9076)
-- Invalid Effect duration & Reflect chance of SC_MAGICMIRROR (NPC_MAGICMIRROR)
-- Wrong usage of script_isstring() for script commands: addspiritball, delspiritball, & countspiritball
* Misc:
-- Moved mail send progress to mail.c mail_send() from clif.c clif_parse_Mail_send()
-- Moved hardcoded flood protection when send a mail to 'mail_delay' in misc.conf

Signed-off-by: Cydh Ramdh <house.bad@gmail.com>
-Fix bugreport:8637 itemcombo bug with card
-Fix weird check reported by cppcheck (Redundant condition at status_readdb_attrfix)
-Fix bugreport:9079 'skill_chk’ differ in signedness [-Wpointer-sign]
-Fix bugreport:9084 getitemX unable to found item by id
-Upd itemdb, itemdb_combo, itemdb_group change key for unsigned int, since they no longer signed
Bugfixed, bugreport:9085. Wrong var in SP_ADD_ITEMGROUP_HEAL_RATE statement.

Signed-off-by: Cydh Ramdh <house.bad@gmail.com>
Bugfix and clean-up
- Added NPC const
- Added checkdragon() in F_CashReset
- Clean-up books.txt, fortune.txt, card_trader.txt, 3rd_trader.txt, stone_change.txt, quests_brasilis.txt
- Minor fix about Weight in comodo_gambling.txt
- Change to F_GM_NPC function in Mercenary Guild Switch follow up bdab851129ceee57a38ccc9d819b42011ef19fb7
- added Mercenary Switch in gm_npcs.txt list
- change to common green maiden in 2010 Headgear Quests

Signed-off-by: Capuche <capucrath@gmail.com>