switch all local imports to relative, to avoid silent mistakes

See merge request !2

The fftw distributor now uses (x, 1) instead of (x,) as inference shape for one-dimensional arrays (important for ffts).

Added int8 as possible dtype. Fixed tests with respect to this issue: https://github.com/numpy/numpy/issues/9290

bincount in _slicing_distributor now tries to preserve a global_type distribution strategy if possible.

Ci



See merge request !1