Log Message:
tex-pxchfon{,-doc}: update to 2.0

This is a major version update, and thus contains breaking changes.
- The obsolete package “pxjafont” is removed.
- The deprecated option “unicode*” (for transitive settings) is removed.
  You must instead use “unicode” now.
- The deprecated command “\asUTF” is removed.
- The option “unicode” has key-value format. You are encouraged to
  use “unicode=simple” instead of “directunicode” now.