move NSAutoReleasePool_wrap() into its own file

[patch by Mike Sliczniak]

Here is a patch to allow compiling of SS and B2 with an SDL Framework. You can
get this by downloading from:

http://www.libsdl.org/release/SDL-1.2.13.dmg

Here is how I tested on an intel 32-bit mac with Mac OS X 10.5.6:

SS ./autogen.sh --disable-standalone-gui --enable-vosf --enable-sdl-framework --enable-sdl-framework-prefix=/Users/mzs/Library/Frameworks --enable-sdl-video --disable-sdl-audio --enable-addressing=real
--without-esd --without-gtk --without-mon --without-x

SS /autogen.sh --disable-standalone-gui --enable-vosf --disable-sdl-framework --disable-sdl-video --disable-sdl-audio --enable-addressing=real --without-esd --without-gtk --without-mon --with-x

B2 ./autogen.sh --disable-standalone-gui --enable-vosf --enable-sdl-framework --enable-sdl-framework-prefix=/Users/mzs/Library/Frameworks --enable-sdl-video --enable-sdl-audio --enable-addressing=real --without-esd --without-gtk --without-mon --without-x --enable-jit-compiler

B2 ./autogen.sh --disable-standalone-gui --enable-vosf --disable-sdl-framework --disable-sdl-video --disable-sdl-audio --enable-addressing=real --with-esd --without-gtk --without-mon --with-x --enable-jit-compiler

(esound does not really work on mac, it needs some better coreaudio patches.)

configure.ac for SS has two little additional fixes so that the Cocoa prefs gui
does not get built if you are building for X11 and so that you can use esd, sdl,
or coreaudio for sound.