Merge pull request #1276 from quantopian/blaze-loader-checkpoints

ENH: add ffill checkpointing to blaze core loader

docs/source/whatsnew/1.0.2.txt

@@ -0,0 +1,23 @@
+Release 1.0.2
+-------------
+
+:Release: 1.0.2
+:Date: TBD
+
+Enhancements
+~~~~~~~~~~~~
+
+- Adds forward fill checkpoint tables for the blaze core loader. This allow the
+  loader to more efficiently forward fill the data by capping the lower date it
+  must search for when querying data. The checkpoints should have novel deltas
+  applied (:issue:`1276`).
+
+Bug Fixes
+~~~~~~~~~
+
+None
+
+Documentation
+~~~~~~~~~~~~~
+
+None