Changes

Ri zm calc6 (#1177)

* Ri_zm calc (Part 6) - Implementing calc_Ri_zm
CLUBB tocket #1145

Eliminating call to calc_stability_correction in advance_xm_wpxp
1) In advance_xm_wpxp_module.F90:
- Eliminated call to calc_stability_correction in calc_xm_wpxp_lhs_terms
- stability_correction is now passed through advance_xm_wpxp to calc_xm_wpxp_lhs_terms
- Cleaned up input lists

2) In advance_clubb_core:
- Adjusted call to advance_xm_wpxp

3) Adjusted spurious_source_test