East-asian-spacing

* Change `Config.skip_monospace_ascii` default to `False`.

* Fix AAT fonts with `kerx` table. The fix is in harfbuzz 2.8.2, which is incorporated into uharfbuzz 0.17.0.
* Add `--monospace` option.

* Add `Config.with_language`
* Add `Config.with_skip_monospace_ascii`
* Update README

Fix the version number.

This release changes the algorithm to avoid adding spacing pairs if glyphs will collide by computing glyph bounding boxes.

A few notable changes:
* The language is now optional. The ink bounding box can discover the used language conventions of the fonts.
* The `Config` class is changed accordingly.

This change does not change the generated tables for Noto CJK. It caused a few changes for Meiryo, but all changes were verified.

* Compute the "fullwidth" advances from glyphs to support:
- non-square fonts.
- incorrect `unitsPerEm` in the `head` table.