SFlow: add simple PHP client
BAC-1258: purge requests monitoring via sFlow
Cleanup
Move sFlow config to wg variables
Run stylize.php
BAC-1256: log method that triggered the purge to sFlow
Log method to both sFlow and Scribe
Merge pull request #2695 from Wikia/bac-1258-sflow-purge-monitoring

Add sFlow monitoring for purges from MW