3.9.15 20170213
* Change JSON float values from string to number according to
http://json.org (#56)
* Add support for exs latched relay module
https://ex-store.de/ESP8266-WiFi-Relay-V31 (#58)
* Add support for inverted relays
* Changed MAX_LOG_LINES from 70 to 60 to preserve memory
3.9.11 20170204
* Fix command I2Cscan
* Fix not allowed spaces in Topic, ButtonTopic and SwitchTopic
* Make all TELEMETRY, STATUS and COMMAND message topics unique (#4)
* Advertise command topic to be used by iobroker (#299)
* Fix butten (non)detection if no GPIO_KEY1 is defined (#13)
* Change WeMo serialnumber from 7 decimal chars to 8 hexadecimal chars
(#18)
* Update web page with Build Date/Time, Emulation and mDNS Discovery and
Advertise information (#21)
3.9.11 20170204
* Fix command I2Cscan
* Fix not allowed spaces in Topic, ButtonTopic and SwitchTopic
* Make all TELEMETRY, STATUS and COMMAND message topics unique (#4)
* Advertise command topic to be used by iobroker (#299)
* Fix butten (non)detection if no GPIO_KEY1 is defined (#13)
* Change WeMo serialnumber from 7 decimal chars to 8 hexadecimal chars
(#18)
* Update web page with Build Date/Time, Emulation and mDNS Discovery and
Advertise information (#21)
3.9.9 20170130
* Add command status 10 showing sensor data
* Fix hlw status messages if hlw is disabled
* Remove GPIO07 and GPIO08 from user selectable (#5)
