Replace std::deque by std::vector
Replace some casts by cpp casts
Move the class and struct declaration to a separate file for clarity.
Fixes db864f10c3 by removing offending function
Refs #5288
Refs D1681
Reviewed by: @vladislavbelov
Differential Revision: https://code.wildfiregames.com/D1682
This was SVN commit r23029.
