drd 7.x-2.0-rc1

After two months of development and testing it's now time for a release candidate

NEW #1422564 by checker: Allow a new server setting to determine if automatic remote installation is supported on that server
NEW: Cron jobs of DRD now only get executed if cron runs in CLI mode
IMPROVEMENT #1418692 by @drvdt: Description of url field and error message improved for initial server installation
IMPROVEMENT: More fine tuned error messages depending on feedback from remote site and offer more and better links to resolve the issue(s)
FIX: Change the array definition for drd operations so that array_merge_deep() works properly
FIX: Add a counter also to info ajax requests
FIX: Do not display the heartbeat info pane toggle for domains that are disabled
FIX: Now make queue runs really work asynched in parallel (thanks to @thorstenmarx)
FIX #1415118: Send back refresh data only of the current object is potentially listed on the current page