GitLab

* README:
* configure.ac:
* nt/README.W32:
* src/msdos.c (internal_terminal_init):
* msdos/sed2v2.inp:
* etc/refcards/ru-refcard.tex: Increment Emacs version to 27.0.50.
* etc/NEWS: New file with sections for Emacs 27.1.
* etc/NEWS.26: Renamed from etc/NEWS.