Fix pets lagging behind and despawning by slightly adjusting speed
if too far from owner.

Closes #8740
Update src/server/game/Entities/Unit/Unit.cpp

Fix crash on "tame pet"
Update src/server/game/Entities/Unit/Unit.cpp

Code style cleanup
Update src/server/game/Entities/Unit/Unit.cpp

Revert codestyle changes to cut down on calls to GetCharmerOrOwner()
DB/Quest: fix some quest linking for Winter Veil
DB/Spell: add aura allowing player to see miscaller soo-gan for a quest

Closes #7868
Various issuetracker fixes

Immunities for Shambling Horror by Valcorb Closes #7541
Flying and  a path for Higherch by Malcrom Closes #7436
SAI for Talonshrike by Nevadas Closes #8639
Merge pull request #8753 from MrSmite/Pet_SpeedFix

Fix pets lagging behind and despawning
Core/Scripting: Add Kirtonos The Herald to c++ scripting. Combat still not finished.
Core/Scripting: Add a few includes to boss_kirtonos_the_herald.
DB: Re-add creature text for SAI conversion
Core/Scripts: Some cleanup for boss_kirtonos_the_herald script
Update src/server/game/Achievements/AchievementMgr.cpp

Prevent achievement completion log spam.
Merge remote-tracking branch 'upstream/master'