Move more calculations to update_history_dyn2_ageclass().

(Also add postprocessing info, where needed.)
- FATES_NPLANT_SZAP
- FATES_NPLANT_CANOPY_SZAP
- FATES_NPLANT_USTORY_SZAP
- FATES_NPLANT_SZAPPF
- FATES_NPATCH_AP
- FATES_CANOPYAREA_AP
- FATES_SECONDAREA_ANTHRODIST_AP
- FATES_SECONDAREA_DIST_AP
- FATES_PATCHAREA_AP
- Unused fire rate-of-spread output