Add unifi

build from aur unifi-controller with the following improvments:
- create user and group to NOT run controller stuff as root
- handle upgrades and remove compilation echo (which was not read by end user)
- java-runtime-headless instead of java-runtimes
- fix java path in service file
- unzip is not a makedepends
- avoid upper case in service and path (UniFi => unifi)
- avoid overwriting of source filename
- cleaning quoting and tabing