Influxdb0.9 line protocol and tags

[v9n]

This does't require any chances on statsd site as other solution. It works by appending tag into metric name, and parse metric name to write tags.

First, disable sanity key checking on config.js of statsd. Then write metric in this format:

metricname#tag1=val1,tag2=val2:value|metrictype|@samplerate

[berglh]

does this method support spaces in the tag values using double quotes?

[alfredocambera]

Tags are really useful. I hope this PR gest merged soon.