[feature_request] Templates: multiple tag matching

[kostasb]

Multiple tag matching for templates does not work.

Multiple measurement matching does work.

Documentation for InfluxDB states that multiple tag matching should work:
https://github.com/influxdata/influxdb/tree/master/services/graphite#multiple-measurement--tags-matching

however such functionality is not referenced under Telegraf's Graphite data input:
https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_INPUT.md#graphite

Telegraf version tested: 0.13.1

Steps to reproduce:

Setup a udp input with graphite format
templates= [".host.host.measurement.cpu.measurement"]

actual input:
services.host123.sfo.performance.1.percent-active 5

results in InfluxDB:
measurement crated: performance.percent-active (multiple measurement matching works)

> select * from "performance.percent-active"
name: performance.percent-active
--------------------------------
time            cpu host    value
1464182865000000000 1   sfo 5

Tag key host has value "sfo" , only holding the latest value matching the "host" templates.
With multiple tag matching enabled this should be host123.sfo