1. add 'latitude' and 'longitude' fields into anno entity in datastore;
2. add 'country' fields into anno entity in datastore;
3. store latitude and longitude that passes from client side;
4. store country by calling google map based on the latitidue and longitude.
Merge pull request #63 from topcircler/master

latitude/longitude/country support
reverse create time order for anno and follow up.
Merge pull request #64 from topcircler/master

reverse create time order for anno and follow up.
Merge remote-tracking branch 'upstream/master'