prefer the venv pybabel but allow the system one to be used (if found)

extract-messages.sh

@@ -1,20 +1,26 @@
 #!/bin/sh
 . ./etc/translation.vars
 
+export TZ=UTC
+
 if [ ! -e $POTDIR ]; then
     mkdir $POTDIR
 fi
 
+# By setting the PYTHONPATH here we can help pybabel find 'our' highlighting
+# extension and we can use any pybabel
+export PYTHONPATH=i2p2www:$PYTHONPATH
+
 if [ $# -ge 1 ]
 then
-    TZ=UTC ./pybabel extract --msgid-bugs-address="http://trac.i2p2.de" \
+    $PYBABEL extract --msgid-bugs-address="http://trac.i2p2.de" \
                                --project=$PROJECT \
                                --version=$VERSION \
                                -F $BABELCFG/$1 \
                                -o $POTDIR/$1.pot $PROJDIR
 else
     for domain in $(ls $BABELCFG); do
-        TZ=UTC ./pybabel extract --msgid-bugs-address="http://trac.i2p2.de" \
+        $PYBABEL extract --msgid-bugs-address="http://trac.i2p2.de" \
                                --project=$PROJECT \
                                --version=$VERSION \
                                -F $BABELCFG/$domain \