Stop NS install symlinking libexec/* into bin/

* Makefile.in (install-arch-dep): NS install no longer needs to
symlink libexec/* into bin/, since 2012-05-14 ns_init_paths change.
* Makefile.in (install-arch-dep): Do not hard-code version number.
NEWS fixes
* Makefile.in (install-arch-dep): Replace use of MV_DIRS with info.
This make it easier to see what is going on.
* Makefile.in (install-arch-dep): Replace use of MV_DIRS with libexec.
* lisp/minibuffer.el (completion--sifn-requote): Handle sifn's truncation
behavior.
(completion--string-equal-p): New function.
(completion--twq-all): Use it to get better assertion failure data.
* lisp/emacs-lisp/pcase.el (pcase-let*, pcase-let): Fix edebug spec.
* Makefile.in (install-arch-dep): Replace last user of MV_DIRS.
Tweak line-breaks in previous change
* src/lread.c (init_obarray): Declare Qt and Qnil as special.
* lisp/minibuffer.el (completion--sifn-requote): Fix last change.
(minibuffer-local-must-match-filename-map):
Move define-obsolete-variable-alias before its var.
* xgselect.c (xg_select): Just invoke 'select' if -nw.

Suggested by Ken Brown.
Try to fix building with gcc >= 4.6 on Darwin.
Eg, hydra builds have been failing for some time because (?) of this.
In gcc < 4.6, unrecognized -no-fo options just cause a warning.
In 4.6 and later, they cause an error.

* configure.in: (CPP): Do not unconditionally set it on Darwin.
Instead, try to test if -no-cpp-precomp is accepted.
(CPP_TEST_OPTIONS, SPECIFIED_CPP): New.
textmodes/flyspell.el: Delay for otherchars as for normal word components.

(flyspell-check-pre-word-p, 
 flyspell-check-word-p, 
 flyspell-debug-signal-word-checked): 

Use for otherchars the same delay used for other word components, so word
is not inmediately checked unless we are in a char that is neither a normal
word component nor an otherchar.
* configure.in: Simplify by removing CPP etc.

(CPP_TEST_OPTIONS, NON_GNU_CPP, cc_specified, SPECIFIED_CFLAGS)
(SPECIFED_CPP, CPP, NON_GNU_CC, AC_PROG_CPP): Remove; not needed.
In particular we no longer need to fiddle with CPP, since we don't
use CPP specially any more.
(gl_EARLY): Invoke this after adjusting CC, so that it uses the
adjusted compiler.
(AC_PROG_INSTALL, AC_PROG_MKDIR_P, AC_PROG_RANLIB): Comment out,
since gl_EARLY and/or Autoconf already does these.
Auto-commit of generated files.
Move word search functions from search.c to isearch.el (bug#10145, bug#11381).

* lisp/isearch.el (word-search-regexp, word-search-backward)
(word-search-forward, word-search-backward-lax)
(word-search-forward-lax): Move functions from search.c.

* src/search.c (Fword_search_regexp, Fword_search_backward)
(Fword_search_forward, Fword_search_backward_lax)
(Fword_search_forward_lax): Move functions to isearch.el.
Install a self-contained NS build's libexec directly into the right place
This is rather than installing it in one place then moving it.

* configure.in (archlibdir): Set it for self-contained ns builds.
(libexecdir): Don't expand it now (this is mainly cosmetic).

* Makefile.in (ns_appbindir, ns_appresdir):
Move them before things that may refer to them.
(install-arch-dep): No need to relocate self-contained ns libexec.

* lib-src/Makefile.in (ns_appbindir): New, set by configure.
Minor optimization for install-arch-dep with self-contained ns build

* Makefile.in (install-arch-dep): For a self-contained ns build,
don't bother installing binaries then immediately deleting them.
Fix previous change, for NS builds that are not self-contained

* configure.in (ns_self_contained): New output variable.
* Makefile.in (ns_self_contained): New, set by configure.
(install-arch-dep): Use $ns_self_contained.