Add missing input file for matrix inversion test program
Eliminate some warnings from GNU compilers with these options: 
"-Wall -Wno-unused-but-set-variable -Wno-write-strings"
Eliminate some warnings from GNU compilers with these options:
"-Wall -Wno-unused-but-set-variable -Wno-write-strings"
Eliminate some warnings from GNU compilers with these options:
"-Wall -Wno-write-strings"
Eliminate some warnings from GNU compilers with these options:
"-Wall -Wno-write-strings"
Merge pull request #1 from GridOPTICS/master

Merge from main GridPACK repository