Removed unused function decrypt_dtc_code
Replaced custom debug utilities with Python logger

As a consequence OBDDevice doesn't need to take a "window" argument
Also some trailing whitespaces (automatically) removed
Cleaned up imports in examples

Removed unused imports
Removed code to alter the Python path
Renamed package pyobdlib to obd
Removed pyobd (the GUI)
Updated copyright notice

Also consolidated copyright file headers
Removed use of deprecated module "string"
Added examples illustrating library functionality

Instead of printing, writing CSV, using SQLite, ...
Removed alien method OBDDevice.log()