- Force long run levels of the exogenous variables to be zero or g (the BGP growth rate of the LHS endogenous variable).
- Fix the correction of the correction for the share λ (aak γ).
- Provisions for the case where the long run level of the exogenous variable is
different from 0 or g (see tmp1 and ll which should be added to the growth
neutrality correction as a constant).
(cherry picked from commit a4423d734e1df1d4ee09c7225d7fd610e0d94cd1)
Also fixes growth neutrality correction in models with non optimizing
agents (correction was not taking into account the value of the share of non
optimizing agents).