Replace `ft_highpow2' function.

* src/pfr/pfrobjs.c (pfr_face_get_kerning): Use `FT_MSB' instead of
`ft_highpow2'.

* src/base/ftutil.c, include/internal/ftobjs.h (ft_highpow2): Remove
it.
Minor.
Whitespace.
Fix Savannah bug #42788.

* src/pfr/pfrobjs.c: Include `ftcalc.h'.
[cff] Fix typo.

* src/cff/cf2hints.c (cf2_glyphpath_computeOffset): Use correct
offsets in third quadrant.

Reported by maks <maksqwe1@ukr.net>.
Minor documentation improvement.
Merge branch 'master' of git://git.sv.nongnu.org/freetype/freetype2