Height offset is not correctly transferred to promoted unit

[sanderd17]

When a unit gets promoted, the height offset gets transferred from the old model to the new one. But this only works with a relative height offset.

When the offset is fixed (m_RelativeToGround == false in CCmpPosition), the offset gets re-applied as relative to the ground.

See ​http://trac.wildfiregames.com/browser/ps/trunk/binaries/data/mods/public/simulation/components/Promotion.js#L47.

To fix it, CCmpPosition would need some changes to be able to do this. With the recent changes to CCmpPosition, I'll wait a bit with the actual implementation to avoid conflicts.

I propose to have the following functions:

void SetHeightOffset(fixed)  -> only set the variable "m_YOffset"
fixed GetHeightOffset()      -> return the variable "m_YOffset" (function unchanged)
void SetHeightFixed(boolean) -> Set m_RelativeToGound = !true/!false (function name gets a complete new meaning)
boolean GetHeightFixed()     -> return !m_RelativeToGround (new function)

With the above changes, Looter.js wouldn't even need to change, and the function names look a lot more logical to me (simple setters and getters should only work on one attribute).

As the meaning of m_RelativeToGround would be the negation of SethHeightFixed and GetHeightFixed, I also propose to rename that variable to m_HeightFixed, and negate the value of it.