Define a "Fortran_FORMAT" target and source file property. Initialize
the target property from a "CMAKE_Fortran_FORMAT" variable. Interpret
values "FIXED" and "FREE" to indicate the source file format. Append
corresponding flags to the compiler command line.
On Linux the NAG Fortran compiler uses gcc under the hood to link. Use
"-Wl,-v" to pass "-v" to the underlying gcc compiler to get verbose link
output. Detect the NAG Fortran directory (using -dryrun) and then honor
object files in the directory referenced in the implicit link line.
Pass real linker options with "-Wl,-Xlinker,". The -Wl, gets through
the NAG front-end and the -Xlinker gets through the gcc front-end.
Brad King