This change enable prefix search on Btrees

The following commits from your working branch will be included:

commit 0a1299c3d72b56a0045385cb9476ab99b1fbd7f6
Author: Abdullah Alamoudi <bamousaa@Abdullahs-MacBook-Pro.local>
Date:   Thu Oct 23 13:49:34 2014 +0300

    Enabled prefix search

Change-Id: Iebefb7c40d6eb7b55d023caaa148cc8512bd6e9e
Reviewed-on: http://fulliautomatix.ics.uci.edu:8443/126
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Taewoo Kim <wangsaeu@gmail.com>
diff --git a/asterix-app/src/test/resources/optimizerts/queries/btree-index/btree-secondary-36.aql b/asterix-app/src/test/resources/optimizerts/queries/btree-index/btree-secondary-36.aql
index 7d72623..894ba63 100644
--- a/asterix-app/src/test/resources/optimizerts/queries/btree-index/btree-secondary-36.aql
+++ b/asterix-app/src/test/resources/optimizerts/queries/btree-index/btree-secondary-36.aql
@@ -6,7 +6,7 @@
  *  Date            : 13th Aug 2012
  */
 
-// Negative test - prefix search, BTree index should NOT be used in the query plan.
+// Positive test - prefix search, BTree index should be used in the query plan.
 
 drop dataverse test if exists;
 create dataverse test;