Merge branch 'release-v4.1'

Merge branch 'release-v4.1'

This merge finalizes the v4.1 release by adding changes from the 'release-v4.1'
branch onto the 'master' branch.

* release-v4.1:
  Remove "(PRE-RELEASE)" from the version number in the README file
  Add 'modis_15s_lake' option for LANDUSEF data in GEOGRID.TBL.ARW
  eliminate the output=no option to the QNC (cloud drop number concentration) variable
  Update grib tables to add new HRRR fields. Ammend one varaible name.
  Leave old code in g2 library's intmath.f code with comment
  Fix string comparison
  Add configuration stanza for POWER running Linux with XL compilers
  Fix mismatch integer kind in IAND intrinsic calls in g2 library
  Update comments in Vtable.GFS. Add history of important GFS changes.
  Adjust pressure-level RH from GEFS as is done for GFS, CDAS, and ECMWF.
  Add LOGSFP entry to METGRID.TBL.ARW
  Update version number to 4.1
  Change Vtable.GFS so the default sea level pressure is MSLET