Server 3.1.0-rc4 released - Bluecherry

FIX: Most reported crashes in RC3 (one still remains outstanding)
FIX: Don't overwrite subdomain SSL certificate include in nginx on upgrade (57bea75)
FIX: Add cronscript to check for new IP address and report changes to subdomain API (#507)
FIX: Available licensed ports show -1 (#504)
FIX: HLS stream is unstable (#487)
FIX: Failed to init muxer for output file $filepath invalid argument
FIX: apt-get remove --purge remove does not truncate (remove) the user, prevents reinstallation (2b3d199)
FEATURE: Update devices.xml to show device name (needed in mobile app) (00e2fc1)
FEATURE: Finished monitoring threads and high performance statistic collector with backend API (#506)