return empty string from currentCompletionText if hint is visible. Close #23.

Author: mgod

SplitwiseTokenExample/src/main/java/com/tokenautocomplete/TokenCompleteTextView.java

@@ -230,6 +230,8 @@ public void allowDuplicates(boolean allow) {
     abstract protected Object defaultObject(String completionText);
 
     protected String currentCompletionText() {
+        if (hintVisible) return ""; //Can't have any text if the hint is visible
+
         Editable editable = getText();
         int end = getSelectionEnd();
         int start = tokenizer.findTokenStart(editable, end);