Secondary BTree indexes can now be created on nullable fields (nulls are filtered during load). Still need to modify insert/delete jobgen to filter nulls as well.

git-svn-id: https://asterixdb.googlecode.com/svn/branches/asterix-fix-issue-9@213 eaa15691-b419-025a-1212-ee371bd00084
diff --git a/asterix-app/src/test/resources/runtimets/results/index/rtree-secondary-index-nullable.adm b/asterix-app/src/test/resources/runtimets/results/index/rtree-secondary-index-nullable.adm
new file mode 100644
index 0000000..2ffad7c
--- /dev/null
+++ b/asterix-app/src/test/resources/runtimets/results/index/rtree-secondary-index-nullable.adm
@@ -0,0 +1 @@
+{ "id": 12 }
\ No newline at end of file