Changes to aprsnear-us.py

Unfortunately because I use 4 spaces rather than tabs the diff is rather
large...

 - Fixed bug 'vechicle'
 - Reformat time to HHMMSS
 - Send comment field to spacenearus
 - Use logging
 - Add main method
 - Refactor config to separate (yaml) file; requires PyYAML
Move config file so that it may be modified without upsetting git
allow specifying alternate spacenearus callsign