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)