Added retrieval of values from database

Added:

• EWIO2 - Metering node is able to retrieve data out of the database
• 'enabled' status as node output (to control dashboard elements)
• Status information as node output

Updated:

• Error handling of websockets

Improved nodes connection

Updated

• metering nodes can connect to different meter on Node-RED flow deploy

Initial release

General

• compatible with EWIO2 firmware 2.0.0

Added

• EWIO2 configuration node: to connect to EWIO2
• EWIO2 - Digital OUT node
• EWIO2 - Analog OUT node
• EWIO2 - Digital IN node
• EWIO2 - Analog IN node
• EWIO2 - Metering node