Improve documentation about PostgreSQL configuration and node version
Improve documentation about PostgreSQL configuration and node version

See https://github.com/CartoDB/cartodb/pull/341

Signed-off-by: Sandro Santilli <3c5c43ca3c88b3a57dd3f125f9ad040c3a915f18@keybit.net>

nuxcode/cartodb,future-analytics/cartodb,codeandtheory/cartodb,DigitalCoder/cartodb,codeandtheory/cartodb,future-analytics/cartodb,dbirchak/cartodb,CartoDB/cartodb,bloomberg/cartodb,DigitalCoder/cartodb,splashblot/dronedb,future-analytics/cartodb,thorncp/cartodb,UCL-ShippingGroup/cartodb-1,DigitalCoder/cartodb,codeandtheory/cartodb,bloomberg/cartodb,future-analytics/cartodb,nuxcode/cartodb,CartoDB/cartodb,thorncp/cartodb,DigitalCoder/cartodb,codeandtheory/cartodb,raquel-ucl/cartodb,bloomberg/cartodb,splashblot/dronedb,UCL-ShippingGroup/cartodb-1,raquel-ucl/cartodb,UCL-ShippingGroup/cartodb-1,thorncp/cartodb,bloomberg/cartodb,bloomberg/cartodb,dbirchak/cartodb,codeandtheory/cartodb,raquel-ucl/cartodb,dbirchak/cartodb,dbirchak/cartodb,splashblot/dronedb,DigitalCoder/cartodb,splashblot/dronedb,nyimbi/cartodb,nyimbi/cartodb,UCL-ShippingGroup/cartodb-1,CartoDB/cartodb,nyimbi/cartodb,thorncp/cartodb,dbirchak/cartodb,nuxcode/cartodb,UCL-ShippingGroup/cartodb-1,future-analytics/cartodb,CartoDB/cartodb,raquel-ucl/cartodb,splashblot/dronedb,CartoDB/cartodb,nuxcode/cartodb,nuxcode/cartodb,thorncp/cartodb,nyimbi/cartodb,raquel-ucl/cartodb,nyimbi/cartodb