py_function_args wasnt working right (was using function namespace for function args), use pythons inspect module instead.
move the function to get a type description into rna_info
- view docs menu item opens sphinx URL
- can be searched (even when local)
- uses rna_info module for introspection
- also documents python defined functions and decorator properties (defined in bpy_types.py)
- experemental python file:line references for python operators.