Switching off window_func_scalar profiling.
Safe fast return in case of input is all masked.
Moving code around.
Handling masked array without interp.
Handling array with masked values and ndim>2.
Cleanning useless stuff.
Spliting the solution for interp and no interp.

Temporary solution, two functions to handle masked arrays. One do
  for no interp and the other for interp.
Extending the solution inter,nointerp for 2Dn.

The arrays with more than 2D are handled by two functions, one for
  interp and other for no interp.
Renaming apply_window_mean_... -> apply_wmean_...
Creating compare2func() @ tests_support
test_Python_x_Cython now uses tests_support.