8.0.0 - Multi Meter Support

• Dual / multi meter support (more than 1 number to be recognized) This is implemented with the feature "number" on the ROI definition as well as selected options
• MQTT: standardization of the naming - including new topics (json, freeMem , uptime)c
• Preparation for extended GPIO support (thanks to Zwerk2k) - not tested and fully functional yet
• Bug fixing: html server, memory leak, MQTT connect, hostname, turn of flash LED