Add forward-compatibility glue with pkg-1.3:

- Use ASSUME_ALWAYS_YES=YES instead of ASSUME_ALWAYS_YES=1
   since pkg-1.3 expects "yes" or "true" values.
 - Before exporting PKG_ABI, strip extra characters from what
   is parsed from 'pkg -vv'.  This causes problems further down
   when creating the packages directory for inclusion on the
   dvd1.iso.  Previously PKG_ABI would be 'freebsd:9:x86:64',
   but now is '"freebsd:9:x86:64";' in pkg-1.3

Tested on:	stable/9@r265858 with ports-mgmt/pkg-devel
MFC After:	3 days
Sponsored by:	The FreeBSD Foundation

release/scripts/pkg-stage.sh

@@ -5,7 +5,7 @@
 
 set -e
 
-export ASSUME_ALWAYS_YES=1
+export ASSUME_ALWAYS_YES="YES"
 export PKG_DBDIR="/tmp/pkg"
 export PERMISSIVE="YES"
 export REPO_AUTOUPDATE="NO"
@@ -40,7 +40,10 @@ if [ ! -x /usr/local/sbin/pkg ]; then
 	/usr/bin/make -C /usr/ports/ports-mgmt/pkg install clean
 fi
 
-export PKG_ABI=$(pkg -vv | grep ^ABI | awk '{print $3}')
+PKG_ABI=$(pkg -vv | grep ^ABI | awk '{print $3}')
+PKG_ABI="${PKG_ABI%\";}"
+PKG_ABI="${PKG_ABI#\"}"
+export PKG_ABI
 export PKG_CACHEDIR="dvd/packages/${PKG_ABI}"
 
 /bin/mkdir -p ${PKG_CACHEDIR}