Make binaries distributed with Emacs work on Android

Make binaries distributed with Emacs work on Android

* doc/lispref/processes.texi (Subprocess Creation): Document
variables containing program names.
* etc/NEWS: Document new variables.
* java/Makefile.in (CROSS_BINS): Add missing etags binary.
* lisp/cedet/semantic/db-ebrowse.el
(semanticdb-create-ebrowse-database):
* lisp/gnus/mail-source.el (mail-source-movemail-program):
* lisp/hexl.el (hexl-program):
* lisp/htmlfontify.el (hfy-etags-bin):
* lisp/ielm.el (inferior-emacs-lisp-mode):
* lisp/mail/rmail.el (rmail-autodetect):
(rmail-insert-inbox-text):
* lisp/org/org-ctags.el (org-ctags-path-to-ctags):
* lisp/progmodes/cperl-mode.el (cperl-etags):
* lisp/speedbar.el (speedbar-fetch-etags-command):
* lisp/textmodes/reftex-global.el (reftex-create-tags-file): Use
new variables.
* src/callproc.c (syms_of_callproc): New variables naming
binaries redistributed with Emacs.