Usefull options for daily use and battery life

If you find the following changes usefull, please take them over so that they are reflected in F-Droid.
Thank you and Merry Christmas.

added autostart option to automatically start the server during bootup
added wifi mode, which will only bind to a local wifi/wlan ip address
instead of all possible (and even global) addresses
changed behaving of notification bar (sticky)
changed behaving of server in wifi mode, server now shuts down and lets
device deep sleep if no wifi is available
changed wake lock from screen dim to partial, a wifi lock should be
aquired if server shuts down but needs to stay on