History bugfixes

[peverwhee]

Summary

1. No longer override averaging flag to "I" if nhtfrq = 1 (every timestep). This reenables subcycling averages.
2. Check for incompatible duplicates
   • compatible duplicates (flags match) are ok - just take the first one (to keep existing CAM behavior)
   • incompatible duplicates (flags differ) - endrun
3. Update git-fleximod to 0.9.2

Mods

src/control/cam_history.F90

• Remove nhtfrq=1 override
• modify list_index to optionally check for duplicates/compatibility
• endrun with message including all duplicates found (if necessary)
  • Sample error message: ERROR: FLDLST: Found duplicate field(s) with different averaging flags. Place in separate fincl lists: "Q:A", "Q:I" (fincl3). "T:A", "T:I" (fincl3). "U:A", "U:I" (fincl4).

bld/namelist_files/use_cases/sd_waccm_sulfur.xml

• remove bad XML comment line

.lib/git-fleximod/

• update to 0.9.2

closes #1149
closes #1150

[brian-eaton]

I'll just point out that the reason for setting the averaging flag to I when nhtfrq=1 is to get the correct timestamps. If the flag is A then the timestamps are set to midpoint values which is not correct for a single timestep.