Log Message:
tex-fontspec{,-doc}: update to 2.7a

## v2.7 (2019/01/24)

* Add new `ScaleAgain` feature for compounding scale factors.
  (This is largely to support `unicode-math` but may be useful by others.)
* `\oldstylenums` no longer overwritten if `textcomp` loaded after
  `fontspec`.
* More fixes for recent regressions (sorry!).

## v2.7a (2019/01/25)

* One last (?!) fix for recent regression (!!). I am not getting enough
  sleep at the moment and it is too hot.
* Add `LocalForms=On/Off/Reset` to control the `locl` OpenType tag.
* Reorganise some documentation.
* Remove redundant redefinition of `\-` which is nowadays defined correctly
  by the LaTeX2e kernel.
* Add code to remove the patching of verbatim commands and environments
  when the new `\verbvisiblespace` command is defined in a future version
  of LaTeX2e.