New implementation for doctest bugfix again for systems without any display already fixed in f41a113131

@yomguy could you please check if this new fix is realy ok for systems without any display
remove some useless graphing tests
skip LiveDecoder doctest (hanging on some systems)
Merge branch 'dev' of github.com:yomguy/TimeSide into dev
Minor changes in live and file decoder and audiosink encoder
Merge : fixes some minor conflicts
Merge branch 'dev' into diadems