[12146] Implement some spells used in the Shade of Aran encounter
[12147] Implement spell 30835
[12148] Improve AreaTrigger teleport requirement checks

Implement AreaLockStatus concept by rsa

Also drop basicly unneeded `areatrigger_teleport`.required_failed_text field.
This concept is still in testing phase, please feedback results of some glitches that might exist!

TODO: Use Player::GetAreaLockStatus or GetAreaTriggerLockStatus for other "CanEnter" checks as well.

Signed-off-by: Schmoozerd <schmoozerd@scriptdev2.com>
[12149] Fix spell 57397. Thanks to koksneo for spotting the error
[12150] Improve target selection for TARGET_DUELVSPLAYER

Also set the spell to be Redirected only if the spell is actually redirected
[12151] Improve EffectTeleUnitsFaceCaster and target-selection for position targets

* Let EffectTeleUnitsFaceCaster use a destination for teleporting if provided
* Expect to add caster for TARGET_RANDOM_NEARBY_LOC, TARGET_RANDOM_CIRCUMFERENCE_POINT only for summon spells (or similar spells)
[12152] Implement spell 42621
[12153] Implement some spells used in the Jan'alai encounter
[12154] Let GetMapEntranceTrigger and GetGoBackTrigger work in a better defined order

Actually as this is still no total order (and it is basicly impossible to define a reasonable total order for areatrigger_teleport) it is not well defined, but probably good enough for all cases
[12155] Rewrite Checks required when entering a map

Expected way from now on is:
- Test if a map can be entered with Player::GetAreaTriggerLockStatus
- IF this doesn't return AREA_LOCKSTATUS_OK, and if wanted,
  send the fail-message with Player::SendTransferAbortedByLockStatus function.

Please feedback any hidden problems!

Signed-off-by: Schmoozerd <schmoozerd@scriptdev2.com>
[12156] Improve the RepopAtGraveyard handling of last commit. Thx to rsa for pointing
[12157] Improve ObjectMgr::GetGoBackTrigger to get back to a trigger that actually ports into the map that could not be entered
[12158] Fixup problems with recent teleportation changes
[12159] Add exception to unneeded check for spell 30009
[12160] Allow SplineMovement flags for vehicles

First author to use the spline movement in vehicle patches unknown, likely names are zergtmn or rsa

Signed-off-by: Schmoozerd <schmoozerd@cmangos>
[12161] Add abstract Board/Unboard Passenger functions to TransportBase

Signed-off-by: Schmoozerd <schmoozerd@cmangos>
[12162] Add generic stackign exception to vehicle control and linkedAura auras

Note: This might not be correct, but aura stacking needs some other serious research, so this should be ok for now.
Signed-off-by: Schmoozerd <schmoozerd@cmangos>
[12163] Improve Initialisation of COMMAND_ATTACK field

This moves the set command of COMMAND_ATTACK out of CharmInfo::InitPetAction bar, so that this function can be used more genericly for other purposes

Signed-off-by: Schmoozerd <cmangos>
[12164] Implement interface for Vehicles

Signed-off-by: Schmoozerd <schmoozerd@cmangos>
[12165] Implement support to track aura targets more genericly

Replace the old SingleTarget aura tracking with a more generic concept, and use this also for CONTROL_VEHICLE auras

Signed-off-by: Schmoozerd <schmoozerd@cmangos>