added grammar and config for navigationTask

ps-config/navigationTask/navigationTask.conf

+[main]
+startdb=43;
+uttdb=47;
+silence=400;
+timeout=8;
+openDeviceDirectly=yes;
+
+[pocketsphinxinstance]
+name=otherCommand;
+#hmm=../../../pocketsphinx/model/en-us/en-us;
+#dict=../../psGrammar/dictionary/tobiDic.dic;
+jsgf=../../psGrammar/navigationTask/navigationTask.jsgf;
+rsbscope=/speechrec/psa/stop;
+bestpath=no;
+autoload=yes;

ps-grammar/navigationTask/navigationTask.jsgf

+#JSGF V1.0;
+grammar navigationTask;
+
+public <navigation> = [tobi] [please] (<stop>);
+<stop> = stop [this];