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/cust-index-age-nullable.adm b/asterix-app/src/test/resources/runtimets/results/index/cust-index-age-nullable.adm
new file mode 100644
index 0000000..f5b5521
--- /dev/null
+++ b/asterix-app/src/test/resources/runtimets/results/index/cust-index-age-nullable.adm
@@ -0,0 +1,2 @@
+{ "cid": 92, "name": "Kenny Laychock", "age": 15, "address": { "number": 4790, "street": "Washington St.", "city": "Portland" }, "interests": {{ "Video Games", "Basketball" }}, "children": [  ] }
+{ "cid": 112, "name": "Dorie Lave", "age": 10, "address": { "number": 2286, "street": "Lake St.", "city": "Los Angeles" }, "interests": {{ "Coffee" }}, "children": [ { "name": "Grady Lave", "age": null }, { "name": "Daysi Lave", "age": null } ] }