Remove vcm removal from compute_globals()

Remove vcm removal from compute_globals()

compute_globals() should only compute and not modify t_state.
Therefore the COM removal is now moved out of compute_globals().
Two separate vcm calls are now moved into one wrapper function.
Now compute_globals() no longer needs fplog and x and v are const.

This change is only refactoring.

Change-Id: I1d6577f2d83fda916421b17fda49d328c4e0a600