[12744] Allow spell cast on non selectable vehicle passengers

This will allow kill credit spells to target vehicle owners (players)

Close scriptdev2/scriptdev2#82
[12745] Implement dummy auras 47563 and 47593
[12746] Fix static analysis const reference performance warnings
[12747] Fix static analysis repeated expression performance warning (1)
[12748] Implement spell effect 19395

Also add missing spells 11756 and 19394. Please note that for spell 11756 only effect0 is implemented. Effect1 it's not mandatory, but would be nice to have in the future.

This will fix quest 2987.
Inspired by the work of @Evildead666