VService.DEFAULT_LOGFILE, --logfile option logs to file instead of stdout
VService.DEFAULT_LOGFILE, --logfile option logs to file instead of stdout

Provide some hooks to allow sparts to log to a file instead of stderr.

bboozzoo/sparts,fmoo/sparts,facebook/sparts,djipko/sparts,bboozzoo/sparts,fmoo/sparts,pshuff/sparts,djipko/sparts,pshuff/sparts,facebook/sparts