This incorporates:
2017-03-14 snippets: move unadjusted snippet sources to lib
2017-03-14 gnulib-tool: fix typo in comment output
2017-03-14 snippets: work around GNU Make 3.82 VPATH
2017-03-13 gnulib-tool: minor --gnu-make fixups
2017-03-12 gnulib-tool: new option --gnu-make
* .gitignore: Remove lib/arg-nonnull.h, lib/c++defs.h,
lib/warn-on-use.h.  Change exception from
build-aux/snippet/_Noreturn.h to lib/_Noreturn.h.
* admin/authors.el (authors-renamed-files-regexps):
* admin/notes/copyright, make-dist:
The snippet files moved from build-aux/snippet to lib.
* lib/_Noreturn.h: Rename from build-aux/snippet/_Noreturn.h.
* lib/arg-nonnull.h: Rename from build-aux/snippet/arg-nonnull.h.
* lib/c++defs.h: Rename from build-aux/snippet/c++defs.h.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* lib/warn-on-use.h: Rename from build-aux/snippet/warn-on-use.h.

This reverts commit c27b645956a11fab1dd8fa189254d525390958f5.

This commit has been reverted because the new mechanism was too
sensitive to changes in the lisp source, generation of new ldefs-boot
files was platform specific and resulted in warnings about undefined
variables.

See also 11436e2890d.

The old code that sets and clears immediate_quit was
ineffective except when Emacs is running in terminal mode, and
has problematic race conditions anyway, so remove it.  This
will introduce some hangs when Emacs runs in terminal mode,
and these hangs should be fixed in followup patches.
* src/keyboard.c (immediate_quit): Remove.  All uses removed.

2e2a806 Fix copyright years by hand
5badc81 Update copyright year to 2017

Run admin/update-copyright.

 * Makefile.in (bootstrap-build,generate-ldefs-boot): New targets.
   (bootstrap): Depend on bootstrap-build.
 * admin/ldefs-clean.el: New file.
 * lisp/Makefile.in (compile-first): Depend on loaddefs.el
 * lisp/ldefs-boot.el: Remove.
 * lisp/ldefs-boot-auto.el: New file.
 * lisp/ldefs-boot-manual.el: New file.
 * lisp/loadup.el: Load ldefs-boot-manual.el.
 * src/emacs.c (generating_ldefs_boot): New variable.
   (main): Check whether we are generating ldefs.
 * src/eval.c (autoload-do-load): Dump autoload forms to stderr when
   requested.
 * src/lisp.h (generating_ldefs_boot): New variable.
 * admin/gitmerge.el, admin/make-tarball.txt, admin/notes/copyright,
   lisp/Makefile.in, lisp/cus-dep.el, lisp/emacs-lisp/elint.el,
   lisp/finder.el, lisp/loadup.el, msdos/mainmake.v2: Update reference to
   ldefs-boot.
 * admin/update_autogen: Alter mechanism for ldefs-boot generation.

b73f466 * lisp/cus-start.el (exec-path): Handle nil elements.  (Bug#2...
55ebb70 Catch the imenu-unavailable error in sh-mode completion table
993acb5 ; Minor fix for last change in characters.el
30c4bb5 More char-width fixes
4eb4463 Fix char-width-table values for some Emoji
528997d Keep point when switching from and to *terminal* buffer
2130005 * INSTALL: Use correct Emacs release number 25.
10835b1 Avoid crashes due to objects read with the #n=object form
4de671d Improve doc string of 'completion-at-point-functions'
ceb46f0 Fix crash in evaluating functions
d8374c4 * src/filelock.c (current_lock_owner): Update comment.

* lisp/international/characters.el (char-width-table): Add missing
range U+1F400..U+1F43E.  (Bug#24699)

* admin/notes/unicode: Mention the need to verify char-width-table
setting against data in EastAsianWidth.txt.

* admin/notes/bug-triage: Do not mention closed bugs, they are
suppressed by default in debbugs-{gnu,org}.

* admin/notes/bug-triage: Stick to the tag "unreproducible", which
debbugs supports, rather than suggesting "doneunreproducible" or
"unreproducable".