Merge from origin/emacs-26

Merge from origin/emacs-26

cb0d40e (origin/emacs-26) Minor change in the manual
7e26d83 More minor changes in the manual
6851754 Replace some obsolete aliases in code
6bcb48c Replace some obsolete aliases in documentation
317da2a Minor improvements in manuals
61c1f80 Minor copyedits in display.texi
d523e4a Remove some unused spam.el variables
501808c Replace some obsolete aliases in code
19afff3 Replace some obsolete aliases in documentation
c797bc9 Merge branch 'emacs-26' of git.savannah.gnu.org:/srv/git/emac...
0efe0bd Obsolete eshell-cmpl-suffix-list
add48d2 More minor changes in the Glossary of the Emacs manual
f6bd7e0 Revert last commit
af4697f Define if-let* and derivatives as aliases for if-let etc
ec79bdc Minor fix in Emacs manual's Glossary