add query completion

We are using ANTLR listeners to find out where in the
query the cursor is. Then we generate a list of keys/values
that might fit at that position. With that information we
can generate new queries and sort them by the number
of results they yield.

pdb-ui/src/main/resources/resources/js/search.js

@@ -12,7 +12,7 @@ $(document).ready(function(){
 		HttpMethod: "GET",
 		Delay: 300,
 		_QueryArg: function() {
-			var caretIndex = document.getElementById('search-input').selectionStart;
+			var caretIndex = document.getElementById('search-input').selectionStart + 1;
 			return 'caretIndex=' + caretIndex + '&query';
 		},
 		_Pre: function() {