font/sfnt: add a Font.Name method.

Also make all of the Buffer fields non-exported. LoadGlyph now returns
the segments instead of setting Buffer.Segments for the caller to use.

Change-Id: I3f87070da5e8f014f88dbca70b62a4cd30e3fd66
Reviewed-on: https://go-review.googlesource.com/34532
Reviewed-by: Dave Day <djd@golang.org>
2 files changed