Solve some MSVC issues with julia.h (Resolves parts of #4937)

Use the macro STATIC_INLINE in julia.h. Furthermore the macro is now
defined for microsoft compilers as “static __inline”. This solves
issues with MSVC when compiling in VS2010.
Lastly, the include of inttypes.h is removed from dtypes.h as it is not
available under MSVC