[12670] Add missing spell id 21883

Close scriptdev2/scriptdev2#106
[12671] Implement ACTION_T_CHANGE_MOVEMENT for EventAI

This will allow changing the creature movement based on eventAI events.

Requested in scriptdev2/scriptdev2-cata#4
[12672] Implement SCRIPT_COMMAND_SEND_AI_EVENT_AROUND for dbscripts engine

This allows more flexibility in interaction between eventAI and dbscripts
[12673] Implement spell effect 42281
[12674] Implement script library hook for NpcSpellClick

Close cmangos/issues#428
Fix bug in debug SendOpcode command

Spotted by Laizerox,
explained by evilwow and tested by Neo.

Operator precedence: ! before >>
[12675] Implement some of the spell effects used in Yogg Saron encounter

Target limit and effect for 63744, 63745 and 63747
Target limit for 62978
Spell effect for 63030
Stacking exception for 65157 and 64775
[12676] All units can have Not_Selectable flag while boarded on vehicle

Thanks to debilvul for pointing
[12677] Make use of GROUP_UPDATE_FLAG_VEHICLE_SEAT

Original patch by thenecromancer (TC)
[12678] Fix possible client crash when passenger despawns while boarded
[12679] Revert [12646]. This needs to be fixed in another way!

Close scriptdev2/scriptdev2#113
[12680] Improve [12678] with additional Vehicle checkes

This is required because transports are not always vehicles
[12681] Fix spell 9712

Fix player spell 9712 used in quests 2203 & 2501. Spell 9712 has NPC target while triggered spell 21029 has self-target (player).

Signed-off-by: Cala Haryon <calaftp@free.fr>
[12682] Disable AI attack for controllable vehicles

This won't allow vehicles which can be controlled to use any type of AI attack
[12683] Implement CreatureLinking Flag DESPAWN_ON_DESPAWN

Thanks to grz3s for testing and feedback.
[12684] Implement more spells for Ulduar

Target limits: 64465 and 63802
Spell effects: 64132, 64172, 65206, 64123, 64131, 64466, 64467 and 64148
Aura stacking 64161 and 65294
[12685] Implement more spells for Yogg-Saron encounter

Spell effects: 63993, 64069 and 65238
Aura proc: 63305 and fix 64148
[12686] Allow SpellClick during combat for dungeons
[12687] Implement sanity spells for Yogg-Saron encounter

Limit target: 63830
Implement dummy aura: 63122 and 63050
Implement spell effects: 64555, 63122, 63795, 65301, 63803, 64164, 64168, 64059

Also
Set positive targets for 63745 and 63747, and update aura proc 63305
[12688] Remove old recastnavigation files