Instance Dungeons Update

As requested by the community in http://hercules.ws/board/topic/1702-implement-rathena-npc/ we're merging in the latest of rAthena's dungeons, this includes the rewriting of all instance dungeons and the addition of 4 dungeons that were not present previously (BakonawaLake, BangungotHospital, BuwayaCave and OldGlastHeim).
Update also includes the ability for instances to reset (or be destroyed if instance files were disabled/removed) upon @reloadscript, instance scripts are able to control to what stage the instances are to be reset via the instance_set_respawn (reload spawn) script command, OnInstanceInit labels are now triggered when the instance starts via instance_init (and upon reload), they may be used alongside instance variables (which are persistent to @reloadscript) to save players' progress.

- NPC Changelog:
-- npc/instances/EndlessTower.txt
--- 2.2 Instance system rewrite. [Euphy]
--- 2.3 Added some missing announcements. [Euphy]
--- 2.4 Added GM management function. [Euphy]
-- npc/instances/NydhoggsNest.txt
--- 1.5 Instance system rewrite. [Euphy]
--- 1.6 Added GM management NPCs. [Euphy]
-- npc/instances/OrcsMemory.txt
--- 1.7 Instance system rewrite. [Euphy]
-- npc/instances/SealedShrine.txt
--- 2.3 Instance system rewrite. [Euphy]
-- npc/other/gm_npcs.txt
--- 1.0 First version. [Euphy]
-- npc/re/instances/BakonawaLake.txt
--- 1.0 First version. [Euphy]
--- 1.1 Added GM management NPC. [Euphy]
-- npc/re/instances/BangungotHospital.txt
--- 1.0 First version. [Euphy]
--- 1.1 Added GM management function. [Euphy]
-- npc/re/instances/BuwayaCave.txt
--- 1.0 First version. [Euphy]
-- npc/re/instances/HazyForest.txt
--- 1.1 Instance system rewrite. [Euphy]
-- npc/re/instances/MalangdoCulvert.txt
--- 1.0b Fixed incorrect use of 'close'. [Joseph]
--- 1.1 Instance system rewrite. [Euphy]
-- npc/re/instances/OctopusCave.txt
--- 1.1 Instance system rewrite. [Euphy]
-- npc/re/instances/OldGlastHeim.txt
--- 1.0 First version. [Euphy]

Special Thanks to Haru, Uziel for their contributions to this update, and ossi0110 for helping us debug it.

Signed-off-by: shennetsind <ind@henn.et>
Merge branch 'master' of https://github.com/HerculesWS/Hercules