FIX: emit `source-name-changed` event with right number of args
FIX: storing sources
FIX: detaching of sources, in case of list
FIX: Mass selection fixed
FIX: Show a message for no selected tracing function
RF: unyfied the access to setting values; method `get_setting`
Merge branch 'fixes'
FIX: Removed obsolete and invalid code
RF: Removed forgotten code from gui