Increase compartmentalization of Nextstep builds rules,

Increase compartmentalization of Nextstep builds rules,
and store Emacs version number in fewer versioned files.

* configure.ac (ns_appsrc): Use relative names.
(ns_frag): Remove.
(Info-gnustep.plist, Emacs.desktop, Info.plist, InfoPlist.strings)
(nextstep/Makefile): Generate these nextstep files.
(SUBDIR_MAKEFILES): Add nextstep.

* Makefile.in (clean, distclean, bootstrap-clean): Add nextstep.

* make-dist (nextstep/templates): Add directory.
(nextstep/Cocoa/Emacs.base/Contents/Resources/English.lproj): Remove.
(nextstep/Cocoa/Emacs.base/Contents)
(nextstep/GNUstep/Emacs.base/Resources): Update contents.

* .bzrignore: Add some nextstep files.

* admin/admin.el (set-version): No more need to set nextstep versions.
(set-copyright): Update for moved nextstep files.

* nextstep/Makefile.in: New file.
* nextstep/templates: New directory.
* nextstep/templates/Emacs.desktop.in, nextstep/templates/Info-gnustep.plist.in:
* nextstep/templates/Info.plist.in, nextstep/templates/InfoPlist.strings.in:
Move here from various Cocoa/, GNUstep/ locations.
Let configure set the version number.
* nextstep/Cocoa/Emacs.base/Contents/Info.plist:
* nextstep/Cocoa/Emacs.base/Contents/Resources/English.lproj/InfoPlist.strings:
* nextstep/GNUstep/Emacs.base/Resources/Info-gnustep.plist:
* nextstep/GNUstep/Emacs.base/Resources/Emacs.desktop: Move to templates/.
* nextstep/Cocoa/Emacs.base/Contents/Resources/English.lproj: Remove directory.

* src/Makefile.in (ns_appdir, ns_appbindir, ns_appsrc): Remove variables.
(ns_frag): Remove.
(ns-app): Move here from ns.mk, and simplify.
(clean): Simplify nextstep entry.
* src/ns.mk: Remove file.