Initial support for an ANTLR-based Influx DB query parser

The initial grammar only understands these queries:
- list series
- select * from my_series
- select * from "312 _ strange\" name"

Two tests check queries which we expect can be parsed and cannot.

The ANTLR Maven plugin builds the lexer and parser during the
generate-sources phase.

This only a first step and the query is not ready to be merged. The goal is to be able the current regular expression based parser first. Later on (in another PR), we can expand the grammar to support more Influx language constructs.

> Am 12.12.2014 um 12:22 schrieb Thomas Segismont <notifications@github.com>:
> That would imply to have two handlers with root path ("/"). I thought it was not possible. Will try.

What is the issue with reserved path-elements? E.g. having /_influx/ where _ is reserved and can not be used
by tenants. The following should (hopefully) allow to separate the roots.

@GET
@Path("/metrics/{tenant:\w+}/...
public void getBla(@Path

and

@GET
@Path("/metrics/_influx/...

Or we could move _influx just one level down /rhq-metrics/_influx  vs /rhq-metrics/metrics/*

> 
> Or sending the tenantId as an Header? "XX-RHQ-METRICS-TENANTID"


Please don't do this, as not every client can be told to support it.
Doing it via the path enables selecting the tenant e.g. in a Grafana config via the base url.