adapted readme to Java 8 and the removed designer (#3067)
adapted readme to Java 8 and the removed designer (#3067)

Signed-off-by: Kai Kreuzer <31ea678c44dc4e8e22ccfd165592dd71a30e46ae@openhab.org>
plamen-peev/smarthome,Snickermicker/smarthome,kceiw/smarthome,neverend92/smarthome,philomatic/smarthome,Mixajlo/smarthome,S0urceror/smarthome,BenediktNiehues/smarthome,neverend92/smarthome,philomatic/smarthome,kceiw/smarthome,Mixajlo/smarthome,BenediktNiehues/smarthome,chaton78/smarthome,ArchibaldLeMagnifique/smarthome,AchimHentschel/smarthome,plamen-peev/smarthome,vkolotov/smarthome,neverend92/smarthome,chaton78/smarthome,S0urceror/smarthome,philomatic/smarthome,BenediktNiehues/smarthome,AchimHentschel/smarthome,plamen-peev/smarthome,chaton78/smarthome,S0urceror/smarthome,Snickermicker/smarthome,Mixajlo/smarthome,vkolotov/smarthome,cdjackson/smarthome,kceiw/smarthome,cdjackson/smarthome,Mixajlo/smarthome,vkolotov/smarthome,Snickermicker/smarthome,cdjackson/smarthome,kceiw/smarthome,neverend92/smarthome,BenediktNiehues/smarthome,philomatic/smarthome,ArchibaldLeMagnifique/smarthome,AchimHentschel/smarthome,S0urceror/smarthome,vkolotov/smarthome,ArchibaldLeMagnifique/smarthome,cdjackson/smarthome,AchimHentschel/smarthome,Snickermicker/smarthome,chaton78/smarthome,plamen-peev/smarthome