Add C and Fortran wrappers for MPI_Init_thread

[wangvsa]

Description

Add C and Fortran wrappers for MPI_Init_thread. Some applications, such as GAMESS and FLASH, use multi-threaded MPI.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Performance enhancement (non-breaking change which improves efficiency)
• Code cleanup (non-breaking change which makes code smaller or more readable)
• Breaking change (fix or feature that would cause existing functionality to change)
• Testing (addition of new tests or update to current tests)
• Documentation (a change to man pages or other documentation)

[CamStan]

Thanks @wangvsa! Just a typo that needs fixed.
Could you also squash any syle/typo fixing commits into the first commit?