change sql schema to reflect changes

Geographic information is saved in the dataset
analyser: Populate geographic information into Redis
in case of error, return error, not nil
add Redis Publish helper function
Publish a data change event into Redis

* make checkdata and checkurl return number of affected urls / metadata entries
* getredisconnect(): add helper functions to retrieve Redis connect string from environment
* redispublish(): add helper to establish a redis connection and publish for a given key an integer (number of affected entries)