vchoi_fork

[svn-r12752] Descripton:  This is a port to G95 compiler for MAC OSX and AIX 5.2

Previous implementation failed to compile on MAC OS X Tiger 10.4 and AIX 5.2

In previous implementation, each overloaded Fortran function called the same
C function. Since declaration of parameters in INTERFACE block for
C Function differed, some compilers issued warnings but g95 on MAC and AIX
failed to compile.

Solution: Add C wrappers corresponding to each overloaded Fortran function
to call C stub function. This fix should also reduce number of warnings
on IRIX systems.

Platforms tested:  MAC OS and AIX 5.2 (copper) with g95;
                   sol (with Sun compilers), heping with PGI compilers