added xiangjian's init script from github

https://gist.github.com/xiangjian/1568696
added a control file with some details
added the webdis binary in /usr/local/bin
added a postinst file to enable and start webdis
added the webdis configuration file to /etc
corrected architecture type
made sure daemonized was set in webdis.json
added a systemctl service that calls the init script
made the postinst script enable and start the webdis service
added the licence as required by Nicolas Favre-Felix of the webdis project
Merge branch 'master' of github.com:AutogrowSystems/debian-webdis-armhf