add grammar for meka demo

psConfig/demos/mekaGrasp.conf

+	[main]
+startdb=43;
+uttdb=47;
+silence=400;
+timeout=8;
+openDeviceDirectly=yes;
+alsadevice=sysdefault;
+
+[pocketsphinxinstance]
+name=confirm;
+jsgf=../../psGrammar/confirm/confirm.jsgf;
+rsbscope=/speechrec/psa/confirm;
+bestpath=no;
+autoload=yes;
+
+
+[pocketsphinxinstance]
+name=drink;
+jsgf=../../psGrammar/object/orderdrink.jsgf;
+rsbscope=/speechrec/psa/drink;
+bestpath=no;
+autoload=yes;
+
+

psGrammar/demos/orderdrink.jsgf

+#JSGF V1.0;
+grammar orderdrink;
+
+public <orderdrink> = ([tobi] [please] give me a <drinks>);
+
+<drinks> = (coke | drink | beer);
+