added Name property to upstream.  used for differentiating mutltiple upstreams in logs and stats
added DateFilter downstream filter that will automatically set the Date header
go fmt
Merge pull request #8 from dgrijalva/date_filter

added DateFilter downstream filter...
swapped value order so request.ID is always logged first
Merge pull request #7 from dgrijalva/named_upstream

added Name property to upstream.