speed(NA): manage NA in input and output of Fortran codes in RunModel functions

- remove the use of the round() function
- replace -999.999 by -99e9
- replace == by <= -99e8
Refs #113
4 jobs for 113-management-of-missing-values-in-input-and-output-of-fortran-codes in 8 minutes and 3 seconds (queued for 6 minutes and 32 seconds)
Status Name Job ID Coverage
  Build
passed build_patched #161321

00:00:27

 
  Regression
passed regression_patched #161322

00:01:02

 
  Tests
passed check_as_cran_patched #161324

00:02:03

passed check_not_cran_patched #161323

00:04:29