[wp] wp-qualif utility script

bin/wp-qualif.sh

+export FRAMAC_WP_CACHE=update
+export FRAMAC_WP_CACHEDIR=$(WP_QUALIF_CACHE)

src/plugins/wp/Makefile.in

@@ -174,10 +174,6 @@ wp-qualif: ./bin/toplevel.opt ./bin/ptests.opt $(WP_QUALIF_CACHE)
 	FRAMAC_WP_CACHEDIR=$(WP_QUALIF_CACHE) \
 	  ./bin/ptests.opt src/plugins/wp/tests -config qualif -error-code
 
-wp-qualif-env:
-	echo "FRAMAC_WP_CACHE=update"
-	echo "FRAMAC_WP_CACHEDIR=$(WP_QUALIF_CACHE)"
-
 wp-qualif-update: ./bin/toplevel.opt ./bin/ptests.opt $(WP_QUALIF_CACHE)
 	@echo "[CACHE] pull cache"
 	@echo "[CACHE] $(WP_QUALIF_CACHE)"

src/plugins/wp/tests/README.md

@@ -105,11 +105,10 @@ environment. To run individual tests, you may now use:
     $ export FRAMAC_WP_CACHEDIR=$WP_QUALIF_CACHE
     $ ./bin/ptests.opt src/plugins/wp/tests/xxx/yyy.i -config qualif [-show|-update]
 
-The necessary environment variables can also be displayed by the makefile:
+An utility script is provided to export the necessary environment variables
+(dont forget the `.` to execute the script in the current shell environment):
 
-    $ make wp-qualif-env
-    FRAMAC_WP_CACHE=update
-    FRAMAC_WP_CACHEDIR=$WP_QUALIF_CACHE
+    $ . bin/wp_qualif.sh
 
 As mentionned above, it is _not_ recommanded to globally set the
 `FRAMAC_WP_XXX` variables in your default shell environment, because WP will