Add 'eventlogging' puppet module

This patch-set adds a puppet module for eventlogging and removes
existing puppet bits from the 'statistics' manifests.

This puppet module configures:
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* 'eventlogging' user
* Python dependencies for eventlogging package
* Log rotation and serving (via rsync) for back-up
* Ganglia monitoring

Change-Id: I8344166836b48f74179533cee09e436a631e759c