IIS: Use total values from WMI and calculate rates in the agent
IIS: Use total bytes values to calculate rates
IIS: Always cast values to a float
3.6.4
Tag IIS metrics by site
IIS: Don't try to normalize site name, use iis_site for metrics
IIS: By default use _Total, but allow a configurable list of sites
Merge branch 'release-3.6.4'

Conflicts:
	checks.d/iis.py
	config.py