axisartist now uses more standard tick direction controls

Previously, the position of axisartist ticks (inside or outside the axes) were set using set_tick_out(bool). They are now set using set_tick_direction("in") (or "out", or "inout"), and respect rcParams["xtick.direction"] (default: 'out') and rcParams["ytick.direction"] (default: 'out'). In particular, they default to pointing outwards, consistently with the rest of the library.

The tick_out parameter of Ticks has been deprecated (use tick_direction instead). The Ticks.get_tick_out method is deprecated (use Ticks.get_tick_direction instead).

The unused locs_angles_labels attribute of Ticks and LabelBase has also been deprecated.