implement layer attribute statistics
update fieldname
dev story - rework geoserver download and exec

download geonode custom geoserver.war instead of vanilla dist,
download and use empty data dir, use jetty-runner for running
make sure settings value matches actual geoserver url
dev story - follow up to 1b01afe7, JAI fix
dev story - follow up to 1b01afe7, fix security

replace the baseUrl for the geoserver geonode client
minor cleanup of imports
dev story - add reset for geoserver datadir
Re-enabled csw tests
Merge pull request #763 from tomkralidis/stats-master

implement layer attribute statistics
use render_to_string for template processing, add count and unique value columns, safeguard exceptions