[FLASH-BUGS] PPM FPE in 2.3 w/Compaq F90

[Colin Mcnally]

Hi,
	This morning's work with 2.3 revealed that on our site we need to 
explicitally initialize the otherwise unused regions of 2 arrays in 
hydro_1d.F90 to avoid crashes due to floating point errors.

The affected file is FLASH2.3/source/hydro/explicit/split/ppm/hydro_1d.F90

The diff of what I did to remedy the problem is:

315,317d314
< ! explicitally initialize array to prevent FPE on Compaq Fortran/Tru64/Alpha
< ! Colin McNally McMaster 2003
<     xnav = 1.0
464,468d460
<
< ! explicitally initialize array to prevent FPE on Compaq Fortran/Tru64/Alpha
< ! Colin McNally McMaster 2003
<
<        avis = 0.0

We are using Compaq Fortran compiler (V5.5-1877)

-Colin McNally