Log Message:
tex-fontspec{,-doc}: update to 2.6g

- v2.6g (2017-11-09)

    * Bugfix for clash introduced with last version. When loading `babel`
      before `fontspec` the following error arose:

          ! Control sequence \latinencoding already defined.

- v2.6f (2017-11-05)

    * Fix loading of Graphite fonts and add a little documentation
      (a better interface is needed, though)

    * Correct and simplify some internal code that fixes a bug in the
      way some fonts are displayed in `\tracingoutput` mode.

    * This also fixes an obscure bug using the API in which a query for
      a selected font feature would test against the upright font in the
      current family regardless of the face/shape actually in use.

    * This package now complies with the `expl3` option `check-declarations`.