macros: Try to use the standard __func__ first in G_STRFUNC
func is part of the C99 standard. FUNCTION is another name for func. Older versions of GCC recognize only this name. However, it is not standardized. For maximum portability, Its recommended to use func. PRETTY_FUNCTION is yet another name for func. However, in C++, PRETTY_FUNCTION contains the type signature of the function as well as its bare name
http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html
Closes #535 (closed)