Store remote records to local

Summary:
After loading remote records to local, should store the records to local, so
logging out does not cause the records to be gone.

Use _.uniq to combine local and remote records instead of having a for-loop to
do it myself.

Test Plan:
1) Log in and create some records (entering some expressions).
2) Logout
3) Clear history
4) Create a record (optional)
5) Login, should see all the records (same as before this patch)
6) Logout, then reload the page
7) All the records should be there (before the patch, you should only see the
record you created in 4))