After a long delay, apologies :)
Added:
* NotCurses: `can_sextant` (`notcurses_cansextant`)
* Notcurses: `linesigs_enable` (`notcurses_linesigs_enable`)
* Notcurses: `linesigs_disable` (`notcurses_linesigs_disable`)
* Pile: `top_with` (`ncpile_top`)
* Pile: `bottom_with` (`ncpile_bottom`)
* Plane: `resize_maximize` (`ncplane_resize_maximize`)
* Plane: `get_abs_x` (`ncplane_abs_x`)
* Plane: `get_abs_y` (`ncplane_abs_y`)
* Plane: `get_abs_yx` (`ncplane_abs_yx`)
* Plane: `load_egc32` (`cell_load_egc32`)
* Plane: `is_descendant_of` (`ncplane_descendant_p`)
* Progbar: new class, wraps `ncprogbar_*`
Changed:
* Plane (ABI break): `at_cursor` overloads now return `int` where
before they returned `bool` because the underlying Notcurses API
only signalled the operation status with the return value while now
it returns actual information.
Added:
* Pile: new class derived from Plane, which implements all the
`ncpile_*` calls
* Plane: `get_parent` (`ncplane_parent`)
* Plane: protected constructor for use by `Pile` (or other derived
classes which cannot provide a valid `ncplane*` when invoking parent
constructor.
* Plane: `set_plane` for use by the derived classes above.
Changed:
* Plane: `to_ncplane` is a `const` method now.
