Corrected initialization of Nfiles in inp_par.F

[arango]

The local variable Nfiles used to count the number of files per field(s) during record splitting was initialized before being allocated in inp_par.F. This caused unexpected behavior in some compilers that do not initialize variable to zero by default. Many thanks to Kate Hedstrom for bringing this to my attention.

I also added the following conditional when computing the Infinity variable that it is needed when coupling with SWAN:

#ifdef SWAN_COUPLING
      Infinity=one/zero
#endif

This is still not a solution but at least is not used everytime that we run ROMS in other applications. Many thanks to Mark Hadfield for ​reporting this.