To address issue #1 filed on GitHub for the Warwick-PCAV/CloverLeaf_OpenMP
repo, a C preprocessor conditional has been added to detect OpenMP
3.0.  If OpenMP 3.0 is detected, the compiler will generate an error
message that helps explain the syntax error caused by the pragma
statement immediately following the check.  Compilers with support
for OpenMP 3.1 or higher will simply bypass this preprocessor check
and the pragma will have its desired effect.