Streamline function docstrings, fix various prints
Replace optparse with argparse and support different audiosinks

Add some error handling and add support for different audiosinks.
The default is gstreamer
Add better error handling and range checking
Addressed all code comments

- Switched all print statements to use print() and
  templates construct
- Fixed all flake8 warnings and errors
- Changed jukebox to use argparse instead of optparse
  This requires Python 2.7 as a minimum

Still has a pending issue with fixing the locked
thread when the audiosink returns an error
Try at debugging stuck issue, no difference
Changed quotes to tick as per coding style, and cleanup var
Streamline logging, add artist name to print
Use logfile for libspotify debug, more debug
Debugging code
Cleaned up the last review comments
Cleaned up input parsing, last few fixes
Merge pull request #112 from ZenithDK/jukebox-cleanup

Jukebox cleanup