Merge from origin/emacs-26

Merge from origin/emacs-26

1fc98ed073 ; Spelling fix
bb396a369c Update Org to v9.1.6
fa582153f7 Use text-pixels values only when saving framesets (Bug#30141)
6b01b9475d Minor improvement in section "Pages" of the usere manual
e8c8bd3de2 Minor improvements in user manual
26b8b92e63 Improve the "Mark" chapter of the user manual
759569fe40 Improve the "Buffers" chapter of the user manual
c2e6d121ff * lisp/term.el (term-send-input): Fix text duplication in ...
854a1c0a61 Improve "Buffers" in the user manual

# Conflicts:
#	etc/NEWS