quelques echo dans le script de creation du virtualenv

bin/polynum-build-virtualenv

@@ -19,6 +19,12 @@ VE=`basename $VEDIR`
 test -d $DIR || "$DIR does not exist (or is not a directory)"
 
 cd $DIR || abort "cannot cd to $DIR"
+
+echo ""
+echo "Build PolyNum virtualenv in $VEDIR"
+echo "(detailed log in $VEDIR/install.log)"
+echo ""
+
 virtualenv --system-site-packages $VE || abort "cannot create virtualenv $VE in $DIR"
 
 cd $VE
@@ -26,3 +32,6 @@ cd $VE
 pip $PIPOPT install -U pip
 pip $PIPOPT install --requirement=/usr/share/doc/polynum/requirements
 
+echo ""
+echo "PolyNum virtualen created in $VEDIR"
+echo ""