Major formatting update to Python library
Major formatting update to Python library

 + Fixed some spelling mistakes
 + Cleaned up tab/space indentation. Previously some of the samples would not
   work if copied/pasted into a Python interpreter because of mixed tabs/spaces
 + Cleared all trailing whitespace
 + Missing quotation marks in some sample code caused mistakes with printing
   messages
 + Added all import statements to some of the examples that already had some
   import statements

NxRLab/ModernRobotics,NxRLab/ModernRobotics