Implement global loot system Fixes #619

This should allow us to emulate lives global tables

The options available to filter tables are min_level, max_level, race,
rare, raid, race, class, bodytype, and zone.

race, class, bodytype, and zone are a pipe | separated list of IDs

utils/sql/git/required/2018_02_10_GlobalLoot.sql

@@ -0,0 +1,19 @@
+ALTER TABLE `npc_types` ADD `skip_global_loot` TINYINT DEFAULT '0';
+ALTER TABLE `npc_types` ADD `rare_spawn` TINYINT DEFAULT '0';
+
+CREATE TABLE global_loot (
+	id INT NOT NULL AUTO_INCREMENT,
+	description varchar(255),
+	loottable_id INT NOT NULL,
+	enabled TINYINT NOT NULL DEFAULT 1,
+	min_level INT NOT NULL DEFAULT 0,
+	max_level INT NOT NULL DEFAULT 0,
+	rare TINYINT NULL,
+	raid TINYINT NULL,
+	race MEDIUMTEXT NULL,
+	class MEDIUMTEXT NULL,
+	bodytype MEDIUMTEXT NULL,
+	zone MEDIUMTEXT NULL,
+	PRIMARY KEY (id)
+);
+