EMI: fix attached actor handling in swamp

Time paradox is now playable.

- local _pos and _yaw values seem to be relative
to the actor where the current actor is attached to

- to accomodate this, Lua_V1::GetVisibleThings,
Actor::getYawTo and Actor::getSimplePuckVector should use
world coordinates
Merge pull request #774 from chkr-private/swamp-fixes

EMI: make time paradox solvable