bug#15112: 24.3; package.el byte compile autoloads

[Kevin Ryde <user42@zip.com.au>]

When package.el installs a file, the foo-autoloads.el which it creates
is not byte compiled.  I hoped that it would be, because doing so allows
the dynamic docstrings stuff to leave possibly big docstrings on disk
until required.

I see package-autoload-ensure-default-file contains

    ";; no-byte-compile: t\n"

which is perhaps copied from autoload-rubric.  Perhaps it could omit
that to allow byte compile.

I have presumed no-byte-compile in loaddefs is for the benefit of emacs'
own loaddefs which are dumped.  Perhaps for everyone else the default
rubric could allow byte compiling.



In GNU Emacs 24.3.1 (i486-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2013-05-29 on blah.blah, modified by Debian
System Description:	Debian GNU/Linux unstable (sid)

Configured using:
 `configure '--build' 'i486-linux-gnu' '--build' 'i486-linux-gnu'
 '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib'
 '--localstatedir=/var/lib' '--infodir=/usr/share/info'
 '--mandir=/usr/share/man' '--with-pop=yes'
 '--enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.3/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.3/site-lisp:/usr/share/emacs/site-lisp'
 '--with-crt-dir=/usr/lib/i386-linux-gnu' '--with-x=yes'
 '--with-x-toolkit=lucid' '--with-toolkit-scroll-bars' '--without-gconf'
 'build_alias=i486-linux-gnu' 'CFLAGS=-g -O2 -fstack-protector
 --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wall'
 'LDFLAGS=-Wl,-z,relro -Wl,-znocombreloc'
 'CPPFLAGS=-D_FORTIFY_SOURCE=2''

Important settings:
  value of $LANG: en_AU
  locale-coding-system: iso-latin-1-unix
  default enable-multibyte-characters: t